18323872640 has 64 divisors (see below), whose sum is σ = 43825062960. Its totient is φ = 7326277632.

The previous prime is 18323872627. The next prime is 18323872661. The reversal of 18323872640 is 4627832381.

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 18323872591 and 18323872600.

It is a congruent number.

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, 1849139 + ... + 1859021.

Almost surely, 2^18323872640 is an apocalyptic number.

18323872640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18323872640 is an abundant number, since it is smaller than the sum of its proper divisors (25501190320).

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

18323872640 is an equidigital number, since it uses as much as digits as its factorization.

18323872640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12799 (or 12787 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 44.

The spelling of 18323872640 in words is "eighteen billion, three hundred twenty-three million, eight hundred seventy-two thousand, six hundred forty".