18857537693 has 2 divisors, whose sum is σ = 18857537694. Its totient is φ = 18857537692.

The previous prime is 18857537687. The next prime is 18857537717. The reversal of 18857537693 is 39673575881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15885325369 + 2972212324 = 126037^2 + 54518^2 .

It is a cyclic number.

It is not a de Polignac number, because 18857537693 - 2⁸ = 18857537437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18857537653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9428768846 + 9428768847.

It is an arithmetic number, because the mean of its divisors is an integer number (9428768847).

Almost surely, 2^18857537693 is an apocalyptic number.

It is an amenable number.

18857537693 is a deficient number, since it is larger than the sum of its proper divisors (1).

18857537693 is an equidigital number, since it uses as much as digits as its factorization.

18857537693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38102400, while the sum is 62.

The spelling of 18857537693 in words is "eighteen billion, eight hundred fifty-seven million, five hundred thirty-seven thousand, six hundred ninety-three".