211220221020 has 96 divisors (see below), whose sum is σ = 598888442880. Its totient is φ = 55614577920.

The previous prime is 211220221019. The next prime is 211220221021. The reversal of 211220221020 is 20122022112.

211220221020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (211220221019) and next prime (211220221021).

It is a super-2 number, since 2×211220221020² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211220221021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9306246 + ... + 9328914.

It is an arithmetic number, because the mean of its divisors is an integer number (6238421280).

Almost surely, 2^211220221020 is an apocalyptic number.

211220221020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211220221020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (299444221440).

211220221020 is an abundant number, since it is smaller than the sum of its proper divisors (387668221860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

211220221020 is a wasteful number, since it uses less digits than its factorization.

211220221020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24635 (or 24633 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 211220221020 its reverse (20122022112), we get a palindrome (231342243132).

The spelling of 211220221020 in words is "two hundred eleven billion, two hundred twenty million, two hundred twenty-one thousand, twenty".