20856208210 has 24 divisors (see below), whose sum is σ = 38791262988. Its totient is φ = 8073367200.

The previous prime is 20856208207. The next prime is 20856208231. The reversal of 20856208210 is 1280265802.

It can be written as a sum of positive squares in 2 ways, for example, as 20716708489 + 139499721 = 143933^2 + 11811^2 .

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1075521 + ... + 1094740.

Almost surely, 2^20856208210 is an apocalyptic number.

20856208210 is a deficient number, since it is larger than the sum of its proper divisors (17935054778).

20856208210 is a wasteful number, since it uses less digits than its factorization.

20856208210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2170330 (or 2170299 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 34.

The spelling of 20856208210 in words is "twenty billion, eight hundred fifty-six million, two hundred eight thousand, two hundred ten".