18636640 has 48 divisors (see below), whose sum is σ = 48036240. Its totient is φ = 6776320.

The previous prime is 18636619. The next prime is 18636661. The reversal of 18636640 is 4663681.

It is an interprime number because it is at equal distance from previous prime (18636619) and next prime (18636661).

It is a junction number, because it is equal to n+sod(n) for n = 18636596 and 18636605.

It is a congruent number.

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, 3535 + ... + 7054.

It is an arithmetic number, because the mean of its divisors is an integer number (1000755).

Almost surely, 2^18636640 is an apocalyptic number.

18636640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18636640 is an abundant number, since it is smaller than the sum of its proper divisors (29399600).

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

18636640 is a wasteful number, since it uses less digits than its factorization.

18636640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10615 (or 10607 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 18636640 is about 4317.0174889616. The cubic root of 18636640 is about 265.1281686876.

The spelling of 18636640 in words is "eighteen million, six hundred thirty-six thousand, six hundred forty".