18518640 has 160 divisors (see below), whose sum is σ = 66948096. Its totient is φ = 4147200.

The previous prime is 18518629. The next prime is 18518651. The reversal of 18518640 is 4681581.

It is an interprime number because it is at equal distance from previous prime (18518629) and next prime (18518651).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 122565 + ... + 122715.

Almost surely, 2^18518640 is an apocalyptic number.

18518640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18518640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33474048).

18518640 is an abundant number, since it is smaller than the sum of its proper divisors (48429456).

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

18518640 is a wasteful number, since it uses less digits than its factorization.

18518640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247 (or 241 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 33.

The square root of 18518640 is about 4303.3289439688. The cubic root of 18518640 is about 264.5674205129.

The spelling of 18518640 in words is "eighteen million, five hundred eighteen thousand, six hundred forty".