18663940 has 24 divisors (see below), whose sum is σ = 39376512. Its totient is φ = 7430880.

The previous prime is 18663929. The next prime is 18663941. The reversal of 18663940 is 4936681.

It is a self number, because there is not a number n which added to its sum of digits gives 18663940.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18663941) 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, 2485 + ... + 6595.

It is an arithmetic number, because the mean of its divisors is an integer number (1640688).

Almost surely, 2^18663940 is an apocalyptic number.

18663940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18663940 is an abundant number, since it is smaller than the sum of its proper divisors (20712572).

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

18663940 is a wasteful number, since it uses less digits than its factorization.

18663940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4347 (or 4345 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 18663940 is about 4320.1782370638. The cubic root of 18663940 is about 265.2575637515.

The spelling of 18663940 in words is "eighteen million, six hundred sixty-three thousand, nine hundred forty".