18190640 has 40 divisors (see below), whose sum is σ = 45549168. Its totient is φ = 6716160.

The previous prime is 18190639. The next prime is 18190661. The reversal of 18190640 is 4609181.

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7706 + ... + 9785.

Almost surely, 2^18190640 is an apocalyptic number.

18190640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18190640 is an abundant number, since it is smaller than the sum of its proper divisors (27358528).

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

18190640 is a wasteful number, since it uses less digits than its factorization.

18190640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17517 (or 17511 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 18190640 is about 4265.0486515396. The cubic root of 18190640 is about 262.9961109171.

The spelling of 18190640 in words is "eighteen million, one hundred ninety thousand, six hundred forty".