18894668537 has 2 divisors, whose sum is σ = 18894668538. Its totient is φ = 18894668536.

The previous prime is 18894668519. The next prime is 18894668543. The reversal of 18894668537 is 73586649881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13242485776 + 5652182761 = 115076^2 + 75181^2 .

It is a cyclic number.

It is not a de Polignac number, because 18894668537 - 2⁸ = 18894668281 is a prime.

It is not a weakly prime, because it can be changed into another prime (18894668557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9447334268 + 9447334269.

It is an arithmetic number, because the mean of its divisors is an integer number (9447334269).

Almost surely, 2^18894668537 is an apocalyptic number.

It is an amenable number.

18894668537 is a deficient number, since it is larger than the sum of its proper divisors (1).

18894668537 is an equidigital number, since it uses as much as digits as its factorization.

18894668537 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69672960, while the sum is 65.

The spelling of 18894668537 in words is "eighteen billion, eight hundred ninety-four million, six hundred sixty-eight thousand, five hundred thirty-seven".