18857537820 has 108 divisors (see below), whose sum is σ = 62874116760. Its totient is φ = 4571519040.

The previous prime is 18857537807. The next prime is 18857537939. The reversal of 18857537820 is 2873575881.

18857537820 is a `hidden beast` number, since 1 + 8 + 85 + 7 + 537 + 8 + 20 = 666.

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 35 ways as a sum of consecutive naturals, for example, 411130 + ... + 454689.

Almost surely, 2^18857537820 is an apocalyptic number.

18857537820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18857537820 is an abundant number, since it is smaller than the sum of its proper divisors (44016578940).

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

18857537820 is a wasteful number, since it uses less digits than its factorization.

18857537820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 865856 (or 865840 counting only the distinct ones).

The product of its (nonzero) digits is 3763200, while the sum is 54.

The spelling of 18857537820 in words is "eighteen billion, eight hundred fifty-seven million, five hundred thirty-seven thousand, eight hundred twenty".