18722540 has 12 divisors (see below), whose sum is σ = 39317376. Its totient is φ = 7489008.

The previous prime is 18722513. The next prime is 18722549. The reversal of 18722540 is 4522781.

It is not an unprimeable number, because it can be changed into a prime (18722549) 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, 468044 + ... + 468083.

It is an arithmetic number, because the mean of its divisors is an integer number (3276448).

Almost surely, 2^18722540 is an apocalyptic number.

18722540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18722540 is an abundant number, since it is smaller than the sum of its proper divisors (20594836).

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

18722540 is a wasteful number, since it uses less digits than its factorization.

18722540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 936136 (or 936134 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 18722540 is about 4326.9550494545. The cubic root of 18722540 is about 265.5348873568.

The spelling of 18722540 in words is "eighteen million, seven hundred twenty-two thousand, five hundred forty".