18368518537 has 4 divisors (see below), whose sum is σ = 18369090256. Its totient is φ = 18367946820.

The previous prime is 18368518523. The next prime is 18368518541. The reversal of 18368518537 is 73581586381.

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: 73581586381 = 22189 ⋅3316129.

It is a cyclic number.

It is not a de Polignac number, because 18368518537 - 2⁷ = 18368518409 is a prime.

It is a super-2 number, since 2×18368518537² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18368519537) 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, 234603 + ... + 302944.

It is an arithmetic number, because the mean of its divisors is an integer number (4592272564).

Almost surely, 2^18368518537 is an apocalyptic number.

It is an amenable number.

18368518537 is a deficient number, since it is larger than the sum of its proper divisors (571719).

18368518537 is an equidigital number, since it uses as much as digits as its factorization.

18368518537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571718.

The product of its digits is 4838400, while the sum is 55.

The spelling of 18368518537 in words is "eighteen billion, three hundred sixty-eight million, five hundred eighteen thousand, five hundred thirty-seven".