18908890 has 64 divisors (see below), whose sum is σ = 45722880. Its totient is φ = 5437440.

The previous prime is 18908881. The next prime is 18908891. The reversal of 18908890 is 9880981.

It is a super-2 number, since 2×18908890² = 715092242064200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18908891) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9066 + ... + 10954.

It is an arithmetic number, because the mean of its divisors is an integer number (714420).

Almost surely, 2^18908890 is an apocalyptic number.

18908890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18908890 is an abundant number, since it is smaller than the sum of its proper divisors (26813990).

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

18908890 is a wasteful number, since it uses less digits than its factorization.

18908890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1927.

The product of its (nonzero) digits is 41472, while the sum is 43.

The square root of 18908890 is about 4348.4353507900. The cubic root of 18908890 is about 266.4129583497.

The spelling of 18908890 in words is "eighteen million, nine hundred eight thousand, eight hundred ninety".