18143720 has 48 divisors (see below), whose sum is σ = 47493540. Its totient is φ = 6220032.

The previous prime is 18143701. The next prime is 18143729. The reversal of 18143720 is 2734181.

It can be written as a sum of positive squares in 2 ways, for example, as 16144324 + 1999396 = 4018^2 + 1414^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18143720.

It is not an unprimeable number, because it can be changed into a prime (18143729) 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, 2669 + ... + 6588.

Almost surely, 2^18143720 is an apocalyptic number.

18143720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18143720 is an abundant number, since it is smaller than the sum of its proper divisors (29349820).

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

18143720 is a wasteful number, since it uses less digits than its factorization.

18143720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9282 (or 9271 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 18143720 is about 4259.5445765950. The cubic root of 18143720 is about 262.7697966829.

The spelling of 18143720 in words is "eighteen million, one hundred forty-three thousand, seven hundred twenty".