18697155397 has 2 divisors, whose sum is σ = 18697155398. Its totient is φ = 18697155396.

The previous prime is 18697155359. The next prime is 18697155427. The reversal of 18697155397 is 79355179681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12098680036 + 6598475361 = 109994^2 + 81231^2 .

It is a cyclic number.

It is not a de Polignac number, because 18697155397 - 2¹⁵ = 18697122629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18697155317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9348577698 + 9348577699.

It is an arithmetic number, because the mean of its divisors is an integer number (9348577699).

Almost surely, 2^18697155397 is an apocalyptic number.

It is an amenable number.

18697155397 is a deficient number, since it is larger than the sum of its proper divisors (1).

18697155397 is an equidigital number, since it uses as much as digits as its factorization.

18697155397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14288400, while the sum is 61.

The spelling of 18697155397 in words is "eighteen billion, six hundred ninety-seven million, one hundred fifty-five thousand, three hundred ninety-seven".