18472859921 has 2 divisors, whose sum is σ = 18472859922. Its totient is φ = 18472859920.

The previous prime is 18472859879. The next prime is 18472859969. The reversal of 18472859921 is 12995827481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12874079296 + 5598780625 = 113464^2 + 74825^2 .

It is a cyclic number.

It is not a de Polignac number, because 18472859921 - 2²⁶ = 18405751057 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18472859221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9236429960 + 9236429961.

It is an arithmetic number, because the mean of its divisors is an integer number (9236429961).

Almost surely, 2^18472859921 is an apocalyptic number.

It is an amenable number.

18472859921 is a deficient number, since it is larger than the sum of its proper divisors (1).

18472859921 is an equidigital number, since it uses as much as digits as its factorization.

18472859921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2903040, while the sum is 56.

The spelling of 18472859921 in words is "eighteen billion, four hundred seventy-two million, eight hundred fifty-nine thousand, nine hundred twenty-one".