18257131 has 2 divisors, whose sum is σ = 18257132. Its totient is φ = 18257130.

The previous prime is 18257111. The next prime is 18257159. The reversal of 18257131 is 13175281.

It is an a-pointer prime, because the next prime (18257159) can be obtained adding 18257131 to its sum of digits (28).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18257131 is a prime.

It is a super-4 number, since 4×18257131⁴ (a number of 30 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 18257131.

It is not a weakly prime, because it can be changed into another prime (18257111) 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 as a sum of consecutive naturals, namely, 9128565 + 9128566.

It is an arithmetic number, because the mean of its divisors is an integer number (9128566).

Almost surely, 2^18257131 is an apocalyptic number.

18257131 is a deficient number, since it is larger than the sum of its proper divisors (1).

18257131 is an equidigital number, since it uses as much as digits as its factorization.

18257131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1680, while the sum is 28.

The square root of 18257131 is about 4272.8364115655. The cubic root of 18257131 is about 263.3161585053.

The spelling of 18257131 in words is "eighteen million, two hundred fifty-seven thousand, one hundred thirty-one".