20856765902 has 16 divisors (see below), whose sum is σ = 35911969920. Its totient is φ = 8899235448.

The previous prime is 20856765901. The next prime is 20856765959. The reversal of 20856765902 is 20956765802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20856765901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3278252 + ... + 3284607.

It is an arithmetic number, because the mean of its divisors is an integer number (2244498120).

Almost surely, 2^20856765902 is an apocalyptic number.

20856765902 is a deficient number, since it is larger than the sum of its proper divisors (15055204018).

20856765902 is a wasteful number, since it uses less digits than its factorization.

20856765902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6563095.

The product of its (nonzero) digits is 1814400, while the sum is 50.

The spelling of 20856765902 in words is "twenty billion, eight hundred fifty-six million, seven hundred sixty-five thousand, nine hundred two".