18640518 has 32 divisors (see below), whose sum is σ = 40322016. Its totient is φ = 5710848.

The previous prime is 18640513. The next prime is 18640541. The reversal of 18640518 is 81504681.

It is a super-2 number, since 2×18640518² = 694937822616648, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18640513) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27196 + ... + 27872.

It is an arithmetic number, because the mean of its divisors is an integer number (1260063).

Almost surely, 2^18640518 is an apocalyptic number.

18640518 is an abundant number, since it is smaller than the sum of its proper divisors (21681498).

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

18640518 is a wasteful number, since it uses less digits than its factorization.

18640518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1048.

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

The square root of 18640518 is about 4317.4666182844. The cubic root of 18640518 is about 265.1465571190.

It can be divided in two parts, 186 and 40518, that added together give a palindrome (40704).

The spelling of 18640518 in words is "eighteen million, six hundred forty thousand, five hundred eighteen".