18744840 has 48 divisors (see below), whose sum is σ = 60921900. Its totient is φ = 4998528.

The previous prime is 18744833. The next prime is 18744841. The reversal of 18744840 is 4844781.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18301284 + 443556 = 4278^2 + 666^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 18744795 and 18744804.

It is not an unprimeable number, because it can be changed into a prime (18744841) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25675 + ... + 26394.

Almost surely, 2^18744840 is an apocalyptic number.

18744840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18744840 is an abundant number, since it is smaller than the sum of its proper divisors (42177060).

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

18744840 is a wasteful number, since it uses less digits than its factorization.

18744840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52086 (or 52079 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 36.

The square root of 18744840 is about 4329.5311524460. The cubic root of 18744840 is about 265.6402697566.

The spelling of 18744840 in words is "eighteen million, seven hundred forty-four thousand, eight hundred forty".