18043720 has 16 divisors (see below), whose sum is σ = 40598460. Its totient is φ = 7217472.

The previous prime is 18043693. The next prime is 18043721. The reversal of 18043720 is 2734081.

It can be written as a sum of positive squares in 2 ways, for example, as 17926756 + 116964 = 4234^2 + 342^2 .

It is not an unprimeable number, because it can be changed into a prime (18043721) 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, 225507 + ... + 225586.

Almost surely, 2^18043720 is an apocalyptic number.

18043720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18043720 is an abundant number, since it is smaller than the sum of its proper divisors (22554740).

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

18043720 is a wasteful number, since it uses less digits than its factorization.

18043720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 451104 (or 451100 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 18043720 is about 4247.7900136424. The cubic root of 18043720 is about 262.2861508511.

The spelling of 18043720 in words is "eighteen million, forty-three thousand, seven hundred twenty".