18900805 has 24 divisors (see below), whose sum is σ = 28498176. Its totient is φ = 11779680.

The previous prime is 18900797. The next prime is 18900823. The reversal of 18900805 is 50800981.

18900805 = 271² + 272² + ... + 424².

It is not a de Polignac number, because 18900805 - 2³ = 18900797 is a prime.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

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, 2004 + ... + 6466.

It is an arithmetic number, because the mean of its divisors is an integer number (1187424).

Almost surely, 2^18900805 is an apocalyptic number.

It is an amenable number.

18900805 is a deficient number, since it is larger than the sum of its proper divisors (9597371).

18900805 is a wasteful number, since it uses less digits than its factorization.

18900805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4497 (or 4486 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 18900805 is about 4347.5056066669. The cubic root of 18900805 is about 266.3749822824.

The spelling of 18900805 in words is "eighteen million, nine hundred thousand, eight hundred five".