18312940 has 24 divisors (see below), whose sum is σ = 39699072. Its totient is φ = 7088640.

The previous prime is 18312929. The next prime is 18312947. The reversal of 18312940 is 4921381.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 18312899 and 18312908.

It is not an unprimeable number, because it can be changed into a prime (18312947) 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, 14149 + ... + 15388.

It is an arithmetic number, because the mean of its divisors is an integer number (1654128).

Almost surely, 2^18312940 is an apocalyptic number.

18312940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18312940 is an abundant number, since it is smaller than the sum of its proper divisors (21386132).

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

18312940 is a wasteful number, since it uses less digits than its factorization.

18312940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29577 (or 29575 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 18312940 is about 4279.3621019960. The cubic root of 18312940 is about 263.5841900863.

The spelling of 18312940 in words is "eighteen million, three hundred twelve thousand, nine hundred forty".