18336973657 has 2 divisors, whose sum is σ = 18336973658. Its totient is φ = 18336973656.

The previous prime is 18336973637. The next prime is 18336973679. The reversal of 18336973657 is 75637963381.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18089981001 + 246992656 = 134499^2 + 15716^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18336973657 is a prime.

It is not a weakly prime, because it can be changed into another prime (18336973607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9168486828 + 9168486829.

It is an arithmetic number, because the mean of its divisors is an integer number (9168486829).

Almost surely, 2^18336973657 is an apocalyptic number.

It is an amenable number.

18336973657 is a deficient number, since it is larger than the sum of its proper divisors (1).

18336973657 is an equidigital number, since it uses as much as digits as its factorization.

18336973657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17146080, while the sum is 58.

The spelling of 18336973657 in words is "eighteen billion, three hundred thirty-six million, nine hundred seventy-three thousand, six hundred fifty-seven".