18190531 has 2 divisors, whose sum is σ = 18190532. Its totient is φ = 18190530.

The previous prime is 18190489. The next prime is 18190537. The reversal of 18190531 is 13509181.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18190531 is a prime.

It is a super-2 number, since 2×18190531² = 661790836123922, which contains 22 as substring.

It is a Chen prime.

It is equal to p_1162639 and since 18190531 and 1162639 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18190531.

It is not a weakly prime, because it can be changed into another prime (18190537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9095265 + 9095266.

It is an arithmetic number, because the mean of its divisors is an integer number (9095266).

Almost surely, 2^18190531 is an apocalyptic number.

18190531 is a deficient number, since it is larger than the sum of its proper divisors (1).

18190531 is an equidigital number, since it uses as much as digits as its factorization.

18190531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 28.

The square root of 18190531 is about 4265.0358732372. The cubic root of 18190531 is about 262.9955856170.

It can be divided in two parts, 18190 and 531, that added together give a triangular number (18721 = T₁₉₃).

The spelling of 18190531 in words is "eighteen million, one hundred ninety thousand, five hundred thirty-one".