18138534636 has 24 divisors (see below), whose sum is σ = 42351637104. Its totient is φ = 6042122560.

The previous prime is 18138534629. The next prime is 18138534683. The reversal of 18138534636 is 63643583181.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 488295 + ... + 524126.

It is an arithmetic number, because the mean of its divisors is an integer number (1764651546).

Almost surely, 2^18138534636 is an apocalyptic number.

It is an amenable number.

18138534636 is an abundant number, since it is smaller than the sum of its proper divisors (24213102468).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18138534636 is a wasteful number, since it uses less digits than its factorization.

18138534636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1013921 (or 1013919 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 48.

The spelling of 18138534636 in words is "eighteen billion, one hundred thirty-eight million, five hundred thirty-four thousand, six hundred thirty-six".