18257031 has 48 divisors (see below), whose sum is σ = 30741984. Its totient is φ = 10340352.

The previous prime is 18257027. The next prime is 18257039. The reversal of 18257031 is 13075281.

It is not a de Polignac number, because 18257031 - 2² = 18257027 is a prime.

It is a super-4 number, since 4×18257031⁴ (a number of 30 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 18256986 and 18257004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18257039) 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 47 ways as a sum of consecutive naturals, for example, 133195 + ... + 133331.

It is an arithmetic number, because the mean of its divisors is an integer number (640458).

Almost surely, 2^18257031 is an apocalyptic number.

18257031 is a deficient number, since it is larger than the sum of its proper divisors (12484953).

18257031 is a wasteful number, since it uses less digits than its factorization.

18257031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240 (or 237 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 18257031 is about 4272.8247097207. The cubic root of 18257031 is about 263.3156777495.

It can be divided in two parts, 18 and 257031, that added together give a square (257049 = 507²).

The spelling of 18257031 in words is "eighteen million, two hundred fifty-seven thousand, thirty-one".