21520421053232 has 20 divisors (see below), whose sum is σ = 41745512855760. Its totient is φ = 10747385477568.

The previous prime is 21520421053231. The next prime is 21520421053289. The reversal of 21520421053232 is 23235012402512.

It is a super-2 number, since 2×21520421053232² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21520421053231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 801551723 + ... + 801578570.

It is an arithmetic number, because the mean of its divisors is an integer number (2087275642788).

Almost surely, 2^{21520421053232} is an apocalyptic number.

It is an amenable number.

21520421053232 is a deficient number, since it is larger than the sum of its proper divisors (20225091802528).

21520421053232 is a wasteful number, since it uses less digits than its factorization.

21520421053232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1603131140 (or 1603131134 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 32.

Adding to 21520421053232 its reverse (23235012402512), we get a palindrome (44755433455744).

The spelling of 21520421053232 in words is "twenty-one trillion, five hundred twenty billion, four hundred twenty-one million, fifty-three thousand, two hundred thirty-two".