18015797 has 2 divisors, whose sum is σ = 18015798. Its totient is φ = 18015796.

The previous prime is 18015779. The next prime is 18015817. The reversal of 18015797 is 79751081.

Together with previous prime (18015779) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17230801 + 784996 = 4151^2 + 886^2 .

It is an emirp because it is prime and its reverse (79751081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18015797 - 2⁸ = 18015541 is a prime.

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 18015797.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18015197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9007898 + 9007899.

It is an arithmetic number, because the mean of its divisors is an integer number (9007899).

Almost surely, 2^18015797 is an apocalyptic number.

It is an amenable number.

18015797 is a deficient number, since it is larger than the sum of its proper divisors (1).

18015797 is an equidigital number, since it uses as much as digits as its factorization.

18015797 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17640, while the sum is 38.

The square root of 18015797 is about 4244.5019731413. The cubic root of 18015797 is about 262.1507833963.

The spelling of 18015797 in words is "eighteen million, fifteen thousand, seven hundred ninety-seven".