18890645956 has 384 divisors, whose sum is σ = 48120791040. Its totient is φ = 6270566400.

The previous prime is 18890645929. The next prime is 18890645989. The reversal of 18890645956 is 65954609881.

It is a junction number, because it is equal to n+sod(n) for n = 18890645894 and 18890645903.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 258775936 + ... + 258776008.

It is an arithmetic number, because the mean of its divisors is an integer number (125314560).

Almost surely, 2^18890645956 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18890645956, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24060395520).

18890645956 is an abundant number, since it is smaller than the sum of its proper divisors (29230145084).

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

18890645956 is a wasteful number, since it uses less digits than its factorization.

18890645956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235 (or 233 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 61.

The spelling of 18890645956 in words is "eighteen billion, eight hundred ninety million, six hundred forty-five thousand, nine hundred fifty-six".