18125531 has 2 divisors, whose sum is σ = 18125532. Its totient is φ = 18125530.

The previous prime is 18125507. The next prime is 18125543. The reversal of 18125531 is 13552181.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18125531 - 2⁶ = 18125467 is a prime.

It is a super-2 number, since 2×18125531² = 657069748063922, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18125531.

It is not a weakly prime, because it can be changed into another prime (18125131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9062765 + 9062766.

It is an arithmetic number, because the mean of its divisors is an integer number (9062766).

Almost surely, 2^18125531 is an apocalyptic number.

18125531 is a deficient number, since it is larger than the sum of its proper divisors (1).

18125531 is an equidigital number, since it uses as much as digits as its factorization.

18125531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1200, while the sum is 26.

The square root of 18125531 is about 4257.4089538122. The cubic root of 18125531 is about 262.6819587997.

The spelling of 18125531 in words is "eighteen million, one hundred twenty-five thousand, five hundred thirty-one".