18541531 has 2 divisors, whose sum is σ = 18541532. Its totient is φ = 18541530.

The previous prime is 18541529. The next prime is 18541541. The reversal of 18541531 is 13514581.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18541531 - 2¹ = 18541529 is a prime.

It is a super-2 number, since 2×18541531² = 687576743647922, which contains 22 as substring.

Together with 18541529, it forms a pair of twin primes.

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 18541531.

It is not a weakly prime, because it can be changed into another prime (18541541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9270765 + 9270766.

It is an arithmetic number, because the mean of its divisors is an integer number (9270766).

Almost surely, 2^18541531 is an apocalyptic number.

18541531 is a deficient number, since it is larger than the sum of its proper divisors (1).

18541531 is an equidigital number, since it uses as much as digits as its factorization.

18541531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2400, while the sum is 28.

The square root of 18541531 is about 4305.9878076929. The cubic root of 18541531 is about 264.6763867430.

The spelling of 18541531 in words is "eighteen million, five hundred forty-one thousand, five hundred thirty-one".