18610640 has 20 divisors (see below), whose sum is σ = 43269924. Its totient is φ = 7444224.

The previous prime is 18610639. The next prime is 18610643. The reversal of 18610640 is 4601681.

It can be written as a sum of positive squares in 2 ways, for example, as 3055504 + 15555136 = 1748^2 + 3944^2 .

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

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18610643) 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, 116237 + ... + 116396.

Almost surely, 2^18610640 is an apocalyptic number.

18610640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18610640 is an abundant number, since it is smaller than the sum of its proper divisors (24659284).

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

18610640 is a wasteful number, since it uses less digits than its factorization.

18610640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232646 (or 232640 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 18610640 is about 4314.0050996725. The cubic root of 18610640 is about 265.0048177598.

The spelling of 18610640 in words is "eighteen million, six hundred ten thousand, six hundred forty".