213311221020 has 144 divisors (see below), whose sum is σ = 649795150368. Its totient is φ = 56641559040.

The previous prime is 213311221001. The next prime is 213311221027. The reversal of 213311221020 is 20122113312.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 213311220984 and 213311221002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213311221027) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 78798507 + ... + 78801213.

It is an arithmetic number, because the mean of its divisors is an integer number (4512466322).

Almost surely, 2^213311221020 is an apocalyptic number.

213311221020 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 213311221020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324897575184).

213311221020 is an abundant number, since it is smaller than the sum of its proper divisors (436483929348).

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

213311221020 is a wasteful number, since it uses less digits than its factorization.

213311221020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4420 (or 4415 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 213311221020 its reverse (20122113312), we get a palindrome (233433334332).

The spelling of 213311221020 in words is "two hundred thirteen billion, three hundred eleven million, two hundred twenty-one thousand, twenty".