18331397 has 8 divisors (see below), whose sum is σ = 21216000. Its totient is φ = 15513264.

The previous prime is 18331381. The next prime is 18331429. The reversal of 18331397 is 79313381.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18331397 - 2⁴ = 18331381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18331367) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 16022 + ... + 17127.

It is an arithmetic number, because the mean of its divisors is an integer number (2652000).

Almost surely, 2^18331397 is an apocalyptic number.

It is an amenable number.

18331397 is a deficient number, since it is larger than the sum of its proper divisors (2884603).

18331397 is an equidigital number, since it uses as much as digits as its factorization.

18331397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33235.

The product of its digits is 13608, while the sum is 35.

The square root of 18331397 is about 4281.5180718993. The cubic root of 18331397 is about 263.6727129176.

The spelling of 18331397 in words is "eighteen million, three hundred thirty-one thousand, three hundred ninety-seven".