21081233524 has 24 divisors (see below), whose sum is σ = 39744475848. Its totient is φ = 9726259200.

The previous prime is 21081233497. The next prime is 21081233527. The reversal of 21081233524 is 42533218012.

It can be written as a sum of positive squares in 4 ways, for example, as 148352400 + 20932881124 = 12180^2 + 144682^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21081233527) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73284 + ... + 218020.

It is an arithmetic number, because the mean of its divisors is an integer number (1656019827).

Almost surely, 2^21081233524 is an apocalyptic number.

It is an amenable number.

21081233524 is a deficient number, since it is larger than the sum of its proper divisors (18663242324).

21081233524 is a wasteful number, since it uses less digits than its factorization.

21081233524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147555 (or 147553 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The spelling of 21081233524 in words is "twenty-one billion, eighty-one million, two hundred thirty-three thousand, five hundred twenty-four".