18997956 has 48 divisors (see below), whose sum is σ = 50198400. Its totient is φ = 6211296.

The previous prime is 18997919. The next prime is 18997969. The reversal of 18997956 is 65979981.

18997956 is nontrivially palindromic in base 13.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4065 + ... + 7383.

It is an arithmetic number, because the mean of its divisors is an integer number (1045800).

Almost surely, 2^18997956 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 18997956, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25099200).

18997956 is an abundant number, since it is smaller than the sum of its proper divisors (31200444).

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

18997956 is a wasteful number, since it uses less digits than its factorization.

18997956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3385 (or 3377 counting only the distinct ones).

The product of its digits is 1224720, while the sum is 54.

The square root of 18997956 is about 4358.6644743545. The cubic root of 18997956 is about 266.8305957344.

The spelling of 18997956 in words is "eighteen million, nine hundred ninety-seven thousand, nine hundred fifty-six".