18002781840 has 80 divisors (see below), whose sum is σ = 57169840896. Its totient is φ = 4683648000.

The previous prime is 18002781821. The next prime is 18002781857. The reversal of 18002781840 is 4818720081.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 904936 + ... + 924615.

Almost surely, 2^18002781840 is an apocalyptic number.

18002781840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18002781840 is an abundant number, since it is smaller than the sum of its proper divisors (39167059056).

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

18002781840 is a wasteful number, since it uses less digits than its factorization.

18002781840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1829608 (or 1829602 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 39.

The spelling of 18002781840 in words is "eighteen billion, two million, seven hundred eighty-one thousand, eight hundred forty".