18997880 has 32 divisors (see below), whose sum is σ = 46632240. Its totient is φ = 6908160.

The previous prime is 18997877. The next prime is 18997889. The reversal of 18997880 is 8879981.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18997889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21149 + ... + 22028.

Almost surely, 2^18997880 is an apocalyptic number.

18997880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18997880 is an abundant number, since it is smaller than the sum of its proper divisors (27634360).

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

18997880 is a wasteful number, since it uses less digits than its factorization.

18997880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43199 (or 43195 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 50.

The square root of 18997880 is about 4358.6557560789. The cubic root of 18997880 is about 266.8302399215.

It can be divided in two parts, 1899 and 7880, that added together give a palindrome (9779).

The spelling of 18997880 in words is "eighteen million, nine hundred ninety-seven thousand, eight hundred eighty".