21356372610 has 72 divisors (see below), whose sum is σ = 56368759356. Its totient is φ = 5609926080.

The previous prime is 21356372593. The next prime is 21356372623. The reversal of 21356372610 is 1627365312.

21356372610 is a `hidden beast` number, since 2 + 1 + 3 + 5 + 6 + 37 + 2 + 610 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 21353100129 + 3272481 = 146127^2 + 1809^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 377580 + ... + 430440.

Almost surely, 2^21356372610 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21356372610, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28184379678).

21356372610 is an abundant number, since it is smaller than the sum of its proper divisors (35012386746).

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

21356372610 is a wasteful number, since it uses less digits than its factorization.

21356372610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53008 (or 52938 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 36.

The spelling of 21356372610 in words is "twenty-one billion, three hundred fifty-six million, three hundred seventy-two thousand, six hundred ten".