18721140 has 48 divisors (see below), whose sum is σ = 53212992. Its totient is φ = 4916736.

The previous prime is 18721127. The next prime is 18721141. The reversal of 18721140 is 4112781.

It is a self number, because there is not a number n which added to its sum of digits gives 18721140.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18721141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1692 + ... + 6348.

It is an arithmetic number, because the mean of its divisors is an integer number (1108604).

Almost surely, 2^18721140 is an apocalyptic number.

18721140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18721140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26606496).

18721140 is an abundant number, since it is smaller than the sum of its proper divisors (34491852).

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

18721140 is a wasteful number, since it uses less digits than its factorization.

18721140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4736 (or 4734 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 24.

The square root of 18721140 is about 4326.7932698478. The cubic root of 18721140 is about 265.5282686304.

The spelling of 18721140 in words is "eighteen million, seven hundred twenty-one thousand, one hundred forty".