18443720 has 16 divisors (see below), whose sum is σ = 41498460. Its totient is φ = 7377472.

The previous prime is 18443717. The next prime is 18443743. The reversal of 18443720 is 2734481.

It can be written as a sum of positive squares in 2 ways, for example, as 17455684 + 988036 = 4178^2 + 994^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 230507 + ... + 230586.

Almost surely, 2^18443720 is an apocalyptic number.

18443720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18443720 is an abundant number, since it is smaller than the sum of its proper divisors (23054740).

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

18443720 is a wasteful number, since it uses less digits than its factorization.

18443720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461104 (or 461100 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 18443720 is about 4294.6152330564. The cubic root of 18443720 is about 264.2101555888.

The spelling of 18443720 in words is "eighteen million, four hundred forty-three thousand, seven hundred twenty".