18863840 has 24 divisors (see below), whose sum is σ = 44566200. Its totient is φ = 7545472.

The previous prime is 18863839. The next prime is 18863843. The reversal of 18863840 is 4836881.

It is a junction number, because it is equal to n+sod(n) for n = 18863794 and 18863803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18863843) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58790 + ... + 59109.

It is an arithmetic number, because the mean of its divisors is an integer number (1856925).

Almost surely, 2^18863840 is an apocalyptic number.

18863840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18863840 is an abundant number, since it is smaller than the sum of its proper divisors (25702360).

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

18863840 is a wasteful number, since it uses less digits than its factorization.

18863840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117914 (or 117906 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 38.

The square root of 18863840 is about 4343.2522376671. The cubic root of 18863840 is about 266.2012158337.

The spelling of 18863840 in words is "eighteen million, eight hundred sixty-three thousand, eight hundred forty".