21120221020 has 48 divisors (see below), whose sum is σ = 46699863840. Its totient is φ = 8001213696.

The previous prime is 21120221011. The next prime is 21120221027. The reversal of 21120221020 is 2012202112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120221027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2112754 + ... + 2122726.

It is an arithmetic number, because the mean of its divisors is an integer number (972913830).

Almost surely, 2^21120221020 is an apocalyptic number.

21120221020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120221020 is an abundant number, since it is smaller than the sum of its proper divisors (25579642820).

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

21120221020 is a wasteful number, since it uses less digits than its factorization.

21120221020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15574 (or 15572 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21120221020 its reverse (2012202112), we get a palindrome (23132423132).

The spelling of 21120221020 in words is "twenty-one billion, one hundred twenty million, two hundred twenty-one thousand, twenty".