21221345562 has 16 divisors (see below), whose sum is σ = 42727543200. Its totient is φ = 7026306512.

The previous prime is 21221345549. The next prime is 21221345603. The reversal of 21221345562 is 26554312212.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11867868 + ... + 11869655.

It is an arithmetic number, because the mean of its divisors is an integer number (2670471450).

Almost surely, 2^21221345562 is an apocalyptic number.

21221345562 is an abundant number, since it is smaller than the sum of its proper divisors (21506197638).

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

21221345562 is a wasteful number, since it uses less digits than its factorization.

21221345562 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23737677.

The product of its digits is 28800, while the sum is 33.

Adding to 21221345562 its reverse (26554312212), we get a palindrome (47775657774).

The spelling of 21221345562 in words is "twenty-one billion, two hundred twenty-one million, three hundred forty-five thousand, five hundred sixty-two".