18307397 has 2 divisors, whose sum is σ = 18307398. Its totient is φ = 18307396.

The previous prime is 18307363. The next prime is 18307409. The reversal of 18307397 is 79370381.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12952801 + 5354596 = 3599^2 + 2314^2 .

It is a cyclic number.

It is not a de Polignac number, because 18307397 - 2⁸ = 18307141 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18307397.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18307307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9153698 + 9153699.

It is an arithmetic number, because the mean of its divisors is an integer number (9153699).

Almost surely, 2^18307397 is an apocalyptic number.

It is an amenable number.

18307397 is a deficient number, since it is larger than the sum of its proper divisors (1).

18307397 is an equidigital number, since it uses as much as digits as its factorization.

18307397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31752, while the sum is 38.

The square root of 18307397 is about 4278.7144097264. The cubic root of 18307397 is about 263.5575933265.

The spelling of 18307397 in words is "eighteen million, three hundred seven thousand, three hundred ninety-seven".