21255211152 has 120 divisors (see below), whose sum is σ = 68085541056. Its totient is φ = 6063752448.

The previous prime is 21255211151. The next prime is 21255211157. The reversal of 21255211152 is 25111255212.

21255211152 is a `hidden beast` number, since 2 + 1 + 25 + 521 + 115 + 2 = 666.

It is a super-2 number, since 2×21255211152² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21255211151) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 666843 + ... + 697989.

Almost surely, 2^21255211152 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21255211152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34042770528).

21255211152 is an abundant number, since it is smaller than the sum of its proper divisors (46830329904).

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

21255211152 is a wasteful number, since it uses less digits than its factorization.

21255211152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31845 (or 31836 counting only the distinct ones).

The product of its digits is 2000, while the sum is 27.

Adding to 21255211152 its reverse (25111255212), we get a palindrome (46366466364).

The spelling of 21255211152 in words is "twenty-one billion, two hundred fifty-five million, two hundred eleven thousand, one hundred fifty-two".