21310561610 has 32 divisors (see below), whose sum is σ = 41324366160. Its totient is φ = 7865722368.

The previous prime is 21310561607. The next prime is 21310561631. The reversal of 21310561610 is 1616501312.

It can be written as a sum of positive squares in 8 ways, for example, as 1053586681 + 20256974929 = 32459^2 + 142327^2 .

It is a super-2 number, since 2×21310561610² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a self number, because there is not a number n which added to its sum of digits gives 21310561610.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 358364 + ... + 413576.

Almost surely, 2^21310561610 is an apocalyptic number.

21310561610 is a deficient number, since it is larger than the sum of its proper divisors (20013804550).

21310561610 is a wasteful number, since it uses less digits than its factorization.

21310561610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58202.

The product of its (nonzero) digits is 1080, while the sum is 26.

The spelling of 21310561610 in words is "twenty-one billion, three hundred ten million, five hundred sixty-one thousand, six hundred ten".