18940840 has 32 divisors (see below), whose sum is σ = 42768000. Its totient is φ = 7549504.

The previous prime is 18940793. The next prime is 18940841. The reversal of 18940840 is 4804981.

It is a junction number, because it is equal to n+sod(n) for n = 18940796 and 18940805.

It is not an unprimeable number, because it can be changed into a prime (18940841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13701 + ... + 15019.

It is an arithmetic number, because the mean of its divisors is an integer number (1336500).

Almost surely, 2^18940840 is an apocalyptic number.

18940840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18940840 is an abundant number, since it is smaller than the sum of its proper divisors (23827160).

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

18940840 is a wasteful number, since it uses less digits than its factorization.

18940840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1689 (or 1685 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 18940840 is about 4352.1075354361. The cubic root of 18940840 is about 266.5629249242.

The spelling of 18940840 in words is "eighteen million, nine hundred forty thousand, eight hundred forty".