20857236678 has 12 divisors (see below), whose sum is σ = 45190679508. Its totient is φ = 6952412220.

The previous prime is 20857236667. The next prime is 20857236749. The reversal of 20857236678 is 87663275802.

20857236678 is a `hidden beast` number, since 2 + 0 + 8 + 572 + 3 + 6 + 67 + 8 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 579367668 + ... + 579367703.

It is an arithmetic number, because the mean of its divisors is an integer number (3765889959).

Almost surely, 2^20857236678 is an apocalyptic number.

20857236678 is an abundant number, since it is smaller than the sum of its proper divisors (24333442830).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20857236678 is a wasteful number, since it uses less digits than its factorization.

20857236678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1158735379 (or 1158735376 counting only the distinct ones).

The product of its (nonzero) digits is 6773760, while the sum is 54.

The spelling of 20857236678 in words is "twenty billion, eight hundred fifty-seven million, two hundred thirty-six thousand, six hundred seventy-eight".