18521908 has 12 divisors (see below), whose sum is σ = 34320132. Its totient is φ = 8716160.

The previous prime is 18521897. The next prime is 18521927. The reversal of 18521908 is 80912581.

It can be written as a sum of positive squares in 2 ways, for example, as 10614564 + 7907344 = 3258^2 + 2812^2 .

It is a super-2 number, since 2×18521908² = 686122151920928, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136123 + ... + 136258.

It is an arithmetic number, because the mean of its divisors is an integer number (2860011).

Almost surely, 2^18521908 is an apocalyptic number.

It is an amenable number.

18521908 is a deficient number, since it is larger than the sum of its proper divisors (15798224).

18521908 is a wasteful number, since it uses less digits than its factorization.

18521908 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272402 (or 272400 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 18521908 is about 4303.7086332604. The cubic root of 18521908 is about 264.5829824094.

The spelling of 18521908 in words is "eighteen million, five hundred twenty-one thousand, nine hundred eight".