21504360664610 has 32 divisors (see below), whose sum is σ = 40045715342640. Its totient is φ = 8304486792448.

The previous prime is 21504360664603. The next prime is 21504360664637. The reversal of 21504360664610 is 1646606340512.

It can be written as a sum of positive squares in 8 ways, for example, as 17164109275681 + 4340251388929 = 4142959^2 + 2083327^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 863264 + ... + 6614676.

Almost surely, 2^{21504360664610} is an apocalyptic number.

21504360664610 is a deficient number, since it is larger than the sum of its proper divisors (18541354678030).

21504360664610 is a wasteful number, since it uses less digits than its factorization.

21504360664610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5764342.

The product of its (nonzero) digits is 622080, while the sum is 44.

The spelling of 21504360664610 in words is "twenty-one trillion, five hundred four billion, three hundred sixty million, six hundred sixty-four thousand, six hundred ten".