18777621056 has 56 divisors (see below), whose sum is σ = 37831142016. Its totient is φ = 9245680640.

The previous prime is 18777621053. The next prime is 18777621073. The reversal of 18777621056 is 65012677781.

It is a hoax number, since the sum of its digits (50) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 18777620995 and 18777621013.

It is not an unprimeable number, because it can be changed into a prime (18777621053) 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, 4982885 + ... + 4986651.

Almost surely, 2^18777621056 is an apocalyptic number.

18777621056 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18777621056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18915571008).

18777621056 is an abundant number, since it is smaller than the sum of its proper divisors (19053520960).

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

18777621056 is a wasteful number, since it uses less digits than its factorization.

18777621056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4947 (or 4937 counting only the distinct ones).

The product of its (nonzero) digits is 987840, while the sum is 50.

The spelling of 18777621056 in words is "eighteen billion, seven hundred seventy-seven million, six hundred twenty-one thousand, fifty-six".