21255204663124 has 12 divisors (see below), whose sum is σ = 37806388622548. Its totient is φ = 10453379342400.

The previous prime is 21255204663109. The next prime is 21255204663131. The reversal of 21255204663124 is 42136640255212.

It can be written as a sum of positive squares in 2 ways, for example, as 5931816123024 + 15323388540100 = 2435532^2 + 3914510^2 .

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, 43555747017 + ... + 43555747504.

Almost surely, 2^{21255204663124} is an apocalyptic number.

It is an amenable number.

21255204663124 is a deficient number, since it is larger than the sum of its proper divisors (16551183959424).

21255204663124 is a wasteful number, since it uses less digits than its factorization.

21255204663124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87111494586 (or 87111494584 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 43.

The spelling of 21255204663124 in words is "twenty-one trillion, two hundred fifty-five billion, two hundred four million, six hundred sixty-three thousand, one hundred twenty-four".