18207572257 has 4 divisors (see below), whose sum is σ = 20808654016. Its totient is φ = 15606490500.

The previous prime is 18207572249. The next prime is 18207572267. The reversal of 18207572257 is 75227570281.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75227570281 = 17 ⋅4425151193.

It is a cyclic number.

It is not a de Polignac number, because 18207572257 - 2³ = 18207572249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18207572267) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1300540869 + ... + 1300540882.

It is an arithmetic number, because the mean of its divisors is an integer number (5202163504).

Almost surely, 2^18207572257 is an apocalyptic number.

It is an amenable number.

18207572257 is a deficient number, since it is larger than the sum of its proper divisors (2601081759).

18207572257 is an equidigital number, since it uses as much as digits as its factorization.

18207572257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2601081758.

The product of its (nonzero) digits is 548800, while the sum is 46.

The spelling of 18207572257 in words is "eighteen billion, two hundred seven million, five hundred seventy-two thousand, two hundred fifty-seven".