18917140 has 36 divisors (see below), whose sum is σ = 43671348. Its totient is φ = 6878080.

The previous prime is 18917123. The next prime is 18917149. The reversal of 18917140 is 4171981.

It can be written as a sum of positive squares in 2 ways, for example, as 2172676 + 16744464 = 1474^2 + 4092^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18917149) 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, 1489 + ... + 6328.

It is an arithmetic number, because the mean of its divisors is an integer number (1213093).

Almost surely, 2^18917140 is an apocalyptic number.

18917140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18917140 is an abundant number, since it is smaller than the sum of its proper divisors (24754208).

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

18917140 is a wasteful number, since it uses less digits than its factorization.

18917140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7848 (or 7835 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 31.

The square root of 18917140 is about 4349.3838644111. The cubic root of 18917140 is about 266.4516982816.

The spelling of 18917140 in words is "eighteen million, nine hundred seventeen thousand, one hundred forty".