18131507 has 2 divisors, whose sum is σ = 18131508. Its totient is φ = 18131506.

The previous prime is 18131501. The next prime is 18131551. The reversal of 18131507 is 70513181.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18131507 - 2²⁴ = 1354291 is a prime.

It is not a weakly prime, because it can be changed into another prime (18131501) 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 as a sum of consecutive naturals, namely, 9065753 + 9065754.

It is an arithmetic number, because the mean of its divisors is an integer number (9065754).

Almost surely, 2^18131507 is an apocalyptic number.

18131507 is a deficient number, since it is larger than the sum of its proper divisors (1).

18131507 is an equidigital number, since it uses as much as digits as its factorization.

18131507 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 840, while the sum is 26.

The square root of 18131507 is about 4258.1107312986. The cubic root of 18131507 is about 262.7108244350.

Adding to 18131507 its reverse (70513181), we get a palindrome (88644688).

The spelling of 18131507 in words is "eighteen million, one hundred thirty-one thousand, five hundred seven".