18431616 has 64 divisors (see below), whose sum is σ = 55961280. Its totient is φ = 5265408.

The previous prime is 18431603. The next prime is 18431627. The reversal of 18431616 is 61613481.

It is a tau number, because it is divible by the number of its divisors (64).

It is a nude number because it is divisible by every one of its digits.

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, 741 + ... + 6116.

It is an arithmetic number, because the mean of its divisors is an integer number (874395).

Almost surely, 2^18431616 is an apocalyptic number.

18431616 is a gapful number since it is divisible by the number (16) 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 18431616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27980640).

18431616 is an abundant number, since it is smaller than the sum of its proper divisors (37529664).

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

18431616 is an equidigital number, since it uses as much as digits as its factorization.

18431616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6881 (or 6869 counting only the distinct ones).

The product of its digits is 3456, while the sum is 30.

The square root of 18431616 is about 4293.2057952071. The cubic root of 18431616 is about 264.1523454948.

The spelling of 18431616 in words is "eighteen million, four hundred thirty-one thousand, six hundred sixteen".