18010640 has 20 divisors (see below), whose sum is σ = 41874924. Its totient is φ = 7204224.

The previous prime is 18010639. The next prime is 18010661. The reversal of 18010640 is 4601081.

It can be written as a sum of positive squares in 2 ways, for example, as 1882384 + 16128256 = 1372^2 + 4016^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112487 + ... + 112646.

Almost surely, 2^18010640 is an apocalyptic number.

18010640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18010640 is an abundant number, since it is smaller than the sum of its proper divisors (23864284).

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

18010640 is a wasteful number, since it uses less digits than its factorization.

18010640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225146 (or 225140 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 18010640 is about 4243.8944378955. The cubic root of 18010640 is about 262.1257675615.

The spelling of 18010640 in words is "eighteen million, ten thousand, six hundred forty".