18390040 has 32 divisors (see below), whose sum is σ = 41640480. Its totient is φ = 7309312.

The previous prime is 18390023. The next prime is 18390049. The reversal of 18390040 is 4009381.

It is a junction number, because it is equal to n+sod(n) for n = 18389987 and 18390014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18390049) 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, 5304 + ... + 8056.

It is an arithmetic number, because the mean of its divisors is an integer number (1301265).

Almost surely, 2^18390040 is an apocalyptic number.

18390040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18390040 is an abundant number, since it is smaller than the sum of its proper divisors (23250440).

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

18390040 is a wasteful number, since it uses less digits than its factorization.

18390040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2931 (or 2927 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 18390040 is about 4288.3609922673. The cubic root of 18390040 is about 263.9535807581.

The spelling of 18390040 in words is "eighteen million, three hundred ninety thousand, forty".