18531797 has 2 divisors, whose sum is σ = 18531798. Its totient is φ = 18531796.

The previous prime is 18531787. The next prime is 18531803. The reversal of 18531797 is 79713581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17901361 + 630436 = 4231^2 + 794^2 .

It is a cyclic number.

It is not a de Polignac number, because 18531797 - 2¹² = 18527701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18531787) 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, 9265898 + 9265899.

It is an arithmetic number, because the mean of its divisors is an integer number (9265899).

Almost surely, 2^18531797 is an apocalyptic number.

It is an amenable number.

18531797 is a deficient number, since it is larger than the sum of its proper divisors (1).

18531797 is an equidigital number, since it uses as much as digits as its factorization.

18531797 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 52920, while the sum is 41.

The square root of 18531797 is about 4304.8573727825. The cubic root of 18531797 is about 264.6300617132.

The spelling of 18531797 in words is "eighteen million, five hundred thirty-one thousand, seven hundred ninety-seven".