21073831560 has 80 divisors (see below), whose sum is σ = 70831500300. Its totient is φ = 5619687552.

The previous prime is 21073831529. The next prime is 21073831609. The reversal of 21073831560 is 6513837012.

21073831560 is a `hidden beast` number, since 2 + 10 + 7 + 3 + 83 + 1 + 560 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20876204196 + 197627364 = 144486^2 + 14058^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3248895 + ... + 3255374.

Almost surely, 2^21073831560 is an apocalyptic number.

21073831560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21073831560 is an abundant number, since it is smaller than the sum of its proper divisors (49757668740).

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

21073831560 is a wasteful number, since it uses less digits than its factorization.

21073831560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6504292 (or 6504279 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The spelling of 21073831560 in words is "twenty-one billion, seventy-three million, eight hundred thirty-one thousand, five hundred sixty".