20956611856 has 20 divisors (see below), whose sum is σ = 40746919312. Its totient is φ = 10441277856.

The previous prime is 20956611827. The next prime is 20956611857. The reversal of 20956611856 is 65811665902.

It is not an unprimeable number, because it can be changed into a prime (20956611857) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2309586 + ... + 2318641.

Almost surely, 2^20956611856 is an apocalyptic number.

It is an amenable number.

20956611856 is a deficient number, since it is larger than the sum of its proper divisors (19790307456).

20956611856 is a wasteful number, since it uses less digits than its factorization.

20956611856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4628518 (or 4628512 counting only the distinct ones).

The product of its (nonzero) digits is 777600, while the sum is 49.

The spelling of 20956611856 in words is "twenty billion, nine hundred fifty-six million, six hundred eleven thousand, eight hundred fifty-six".