18724940 has 24 divisors (see below), whose sum is σ = 42347760. Its totient is φ = 6913728.

The previous prime is 18724931. The next prime is 18724949. The reversal of 18724940 is 4942781.

It is an interprime number because it is at equal distance from previous prime (18724931) and next prime (18724949).

It is a self number, because there is not a number n which added to its sum of digits gives 18724940.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18724949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35750 + ... + 36269.

It is an arithmetic number, because the mean of its divisors is an integer number (1764490).

Almost surely, 2^18724940 is an apocalyptic number.

18724940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18724940 is an abundant number, since it is smaller than the sum of its proper divisors (23622820).

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

18724940 is a wasteful number, since it uses less digits than its factorization.

18724940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72041 (or 72039 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 18724940 is about 4327.2323718516. The cubic root of 18724940 is about 265.5462329773.

The spelling of 18724940 in words is "eighteen million, seven hundred twenty-four thousand, nine hundred forty".