20856945944 has 8 divisors (see below), whose sum is σ = 39106773660. Its totient is φ = 10428472968.

The previous prime is 20856945919. The next prime is 20856945971. The reversal of 20856945944 is 44954965802.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×20856945944² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20856945944.

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 as a sum of consecutive naturals, namely, 1303559114 + ... + 1303559129.

Almost surely, 2^20856945944 is an apocalyptic number.

It is an amenable number.

20856945944 is a deficient number, since it is larger than the sum of its proper divisors (18249827716).

20856945944 is a wasteful number, since it uses less digits than its factorization.

20856945944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2607118249 (or 2607118245 counting only the distinct ones).

The product of its (nonzero) digits is 12441600, while the sum is 56.

The spelling of 20856945944 in words is "twenty billion, eight hundred fifty-six million, nine hundred forty-five thousand, nine hundred forty-four".