18501605873 has 2 divisors, whose sum is σ = 18501605874. Its totient is φ = 18501605872.

The previous prime is 18501605849. The next prime is 18501605887. The reversal of 18501605873 is 37850610581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17930013409 + 571592464 = 133903^2 + 23908^2 .

It is a cyclic number.

It is not a de Polignac number, because 18501605873 - 2⁶ = 18501605809 is a prime.

It is not a weakly prime, because it can be changed into another prime (18501605833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9250802936 + 9250802937.

It is an arithmetic number, because the mean of its divisors is an integer number (9250802937).

Almost surely, 2^18501605873 is an apocalyptic number.

It is an amenable number.

18501605873 is a deficient number, since it is larger than the sum of its proper divisors (1).

18501605873 is an equidigital number, since it uses as much as digits as its factorization.

18501605873 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 201600, while the sum is 44.

The spelling of 18501605873 in words is "eighteen billion, five hundred one million, six hundred five thousand, eight hundred seventy-three".