18159940 has 12 divisors (see below), whose sum is σ = 38135916. Its totient is φ = 7263968.

The previous prime is 18159923. The next prime is 18159941. The reversal of 18159940 is 4995181.

It can be written as a sum of positive squares in 2 ways, for example, as 13133376 + 5026564 = 3624^2 + 2242^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18159940.

It is not an unprimeable number, because it can be changed into a prime (18159941) 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, 453979 + ... + 454018.

It is an arithmetic number, because the mean of its divisors is an integer number (3177993).

Almost surely, 2^18159940 is an apocalyptic number.

18159940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18159940 is an abundant number, since it is smaller than the sum of its proper divisors (19975976).

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

18159940 is a wasteful number, since it uses less digits than its factorization.

18159940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 908006 (or 908004 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 18159940 is about 4261.4481106779. The cubic root of 18159940 is about 262.8480764156.

The spelling of 18159940 in words is "eighteen million, one hundred fifty-nine thousand, nine hundred forty".