20870156656 has 20 divisors (see below), whose sum is σ = 41528792632. Its totient is φ = 10153048896.

The previous prime is 20870156647. The next prime is 20870156669. The reversal of 20870156656 is 65665107802.

It is a super-2 number, since 2×20870156656² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 17626230 + ... + 17627413.

Almost surely, 2^20870156656 is an apocalyptic number.

It is an amenable number.

20870156656 is a deficient number, since it is larger than the sum of its proper divisors (20658635976).

20870156656 is a wasteful number, since it uses less digits than its factorization.

20870156656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35253688 (or 35253682 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 46.

The spelling of 20870156656 in words is "twenty billion, eight hundred seventy million, one hundred fifty-six thousand, six hundred fifty-six".