18308997 has 40 divisors (see below), whose sum is σ = 31944000. Its totient is φ = 10446408.

The previous prime is 18308987. The next prime is 18308999. The reversal of 18308997 is 79980381.

It is not a de Polignac number, because 18308997 - 2⁴ = 18308981 is a prime.

It is a super-2 number, since 2×18308997² = 670438742292018, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18308999) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 27454 + ... + 28112.

It is an arithmetic number, because the mean of its divisors is an integer number (798600).

Almost surely, 2^18308997 is an apocalyptic number.

It is an amenable number.

18308997 is a deficient number, since it is larger than the sum of its proper divisors (13635003).

18308997 is an frugal number, since it uses more digits than its factorization.

18308997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 692 (or 669 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The square root of 18308997 is about 4278.9013776903. The cubic root of 18308997 is about 263.5652710949.

The spelling of 18308997 in words is "eighteen million, three hundred eight thousand, nine hundred ninety-seven".