18390031 has 8 divisors (see below), whose sum is σ = 20754000. Its totient is φ = 16141440.

The previous prime is 18390023. The next prime is 18390049. The reversal of 18390031 is 13009381.

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 18390031 - 2³ = 18390023 is a prime.

It is a super-2 number, since 2×18390031² = 676386480361922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18389978 and 18390005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18390091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28506 + ... + 29143.

It is an arithmetic number, because the mean of its divisors is an integer number (2594250).

Almost surely, 2^18390031 is an apocalyptic number.

18390031 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18390031 is a deficient number, since it is larger than the sum of its proper divisors (2363969).

18390031 is a wasteful number, since it uses less digits than its factorization.

18390031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57689.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 18390031 is about 4288.3599429152. The cubic root of 18390031 is about 263.9535376988.

The spelling of 18390031 in words is "eighteen million, three hundred ninety thousand, thirty-one".