18943117956 has 243 divisors, whose sum is σ = 58203809391. Its totient is φ = 5179442688.

The previous prime is 18943117939. The next prime is 18943117967. The reversal of 18943117956 is 65971134981.

The square root of 18943117956 is 137634.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 6536722500 + 12406395456 = 80850^2 + 111384^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 167638156 + ... + 167638268.

Almost surely, 2^18943117956 is an apocalyptic number.

18943117956 is the 137634-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18943117956

18943117956 is an abundant number, since it is smaller than the sum of its proper divisors (39260691435).

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

18943117956 is a wasteful number, since it uses less digits than its factorization.

18943117956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308 (or 154 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 54.

The spelling of 18943117956 in words is "eighteen billion, nine hundred forty-three million, one hundred seventeen thousand, nine hundred fifty-six".