18321465257 has 4 divisors (see below), whose sum is σ = 18442799616. Its totient is φ = 18200130900.

The previous prime is 18321465181. The next prime is 18321465259. The reversal of 18321465257 is 75256412381.

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: 75256412381 = 4793 ⋅15701317.

It is a cyclic number.

It is not a de Polignac number, because 18321465257 - 2¹² = 18321461161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18321465259) 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, 60666953 + ... + 60667254.

It is an arithmetic number, because the mean of its divisors is an integer number (4610699904).

Almost surely, 2^18321465257 is an apocalyptic number.

It is an amenable number.

18321465257 is a deficient number, since it is larger than the sum of its proper divisors (121334359).

18321465257 is a wasteful number, since it uses less digits than its factorization.

18321465257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121334358.

The product of its digits is 403200, while the sum is 44.

The spelling of 18321465257 in words is "eighteen billion, three hundred twenty-one million, four hundred sixty-five thousand, two hundred fifty-seven".