18257213215 has 32 divisors (see below), whose sum is σ = 23036682240. Its totient is φ = 13874073984.

The previous prime is 18257213159. The next prime is 18257213237. The reversal of 18257213215 is 51231275281.

It is a cyclic number.

It is not a de Polignac number, because 18257213215 - 2¹⁷ = 18257082143 is a prime.

It is a super-4 number, since 4×18257213215⁴ (a number of 42 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3814714 + ... + 3819496.

It is an arithmetic number, because the mean of its divisors is an integer number (719896320).

Almost surely, 2^18257213215 is an apocalyptic number.

18257213215 is a deficient number, since it is larger than the sum of its proper divisors (4779469025).

18257213215 is a wasteful number, since it uses less digits than its factorization.

18257213215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5311.

The product of its digits is 33600, while the sum is 37.

Adding to 18257213215 its reverse (51231275281), we get a palindrome (69488488496).

The spelling of 18257213215 in words is "eighteen billion, two hundred fifty-seven million, two hundred thirteen thousand, two hundred fifteen".