18880640 has 32 divisors (see below), whose sum is σ = 45138060. Its totient is φ = 7552000.

The previous prime is 18880639. The next prime is 18880669. The reversal of 18880640 is 4608881.

It can be written as a sum of positive squares in 2 ways, for example, as 18593344 + 287296 = 4312^2 + 536^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a self number, because there is not a number n which added to its sum of digits gives 18880640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14111 + ... + 15390.

Almost surely, 2^18880640 is an apocalyptic number.

18880640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18880640 is an abundant number, since it is smaller than the sum of its proper divisors (26257420).

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

18880640 is an equidigital number, since it uses as much as digits as its factorization.

18880640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29520 (or 29508 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 35.

The square root of 18880640 is about 4345.1858418254. The cubic root of 18880640 is about 266.2802180137.

The spelling of 18880640 in words is "eighteen million, eight hundred eighty thousand, six hundred forty".