21623135312 has 20 divisors (see below), whose sum is σ = 44359226676. Its totient is φ = 10175592960.

The previous prime is 21623135293. The next prime is 21623135333. The reversal of 21623135312 is 21353132612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18698921536 + 2924213776 = 136744^2 + 54076^2 .

It is a super-2 number, since 2×21623135312² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39748139 + ... + 39748682.

Almost surely, 2^21623135312 is an apocalyptic number.

It is an amenable number.

21623135312 is an abundant number, since it is smaller than the sum of its proper divisors (22736091364).

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

21623135312 is a wasteful number, since it uses less digits than its factorization.

21623135312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79496846 (or 79496840 counting only the distinct ones).

The product of its digits is 6480, while the sum is 29.

Adding to 21623135312 its reverse (21353132612), we get a palindrome (42976267924).

The spelling of 21623135312 in words is "twenty-one billion, six hundred twenty-three million, one hundred thirty-five thousand, three hundred twelve".