18991050 has 48 divisors (see below), whose sum is σ = 50725920. Its totient is φ = 4674240.

The previous prime is 18991043. The next prime is 18991061. The reversal of 18991050 is 5019981.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2920 + ... + 6819.

It is an arithmetic number, because the mean of its divisors is an integer number (1056790).

Almost surely, 2^18991050 is an apocalyptic number.

18991050 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18991050 is an abundant number, since it is smaller than the sum of its proper divisors (31734870).

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

18991050 is a wasteful number, since it uses less digits than its factorization.

18991050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9767 (or 9762 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 33.

The square root of 18991050 is about 4357.8721872033. The cubic root of 18991050 is about 266.7982597044.

The spelling of 18991050 in words is "eighteen million, nine hundred ninety-one thousand, fifty".