18821908 has 48 divisors (see below), whose sum is σ = 38993920. Its totient is φ = 7783776.

The previous prime is 18821903. The next prime is 18821921. The reversal of 18821908 is 80912881.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18821903) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 148141 + ... + 148267.

Almost surely, 2^18821908 is an apocalyptic number.

It is an amenable number.

18821908 is an abundant number, since it is smaller than the sum of its proper divisors (20172012).

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

18821908 is a wasteful number, since it uses less digits than its factorization.

18821908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284 (or 282 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 37.

The square root of 18821908 is about 4338.4222938760. The cubic root of 18821908 is about 266.0038252978.

The spelling of 18821908 in words is "eighteen million, eight hundred twenty-one thousand, nine hundred eight".