18791616 has 56 divisors (see below), whose sum is σ = 50281840. Its totient is φ = 6193152.

The previous prime is 18791609. The next prime is 18791639. The reversal of 18791616 is 61619781.

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, 18120 + ... + 19128.

It is an arithmetic number, because the mean of its divisors is an integer number (897890).

Almost surely, 2^18791616 is an apocalyptic number.

18791616 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 18791616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25140920).

18791616 is an abundant number, since it is smaller than the sum of its proper divisors (31490224).

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

18791616 is a wasteful number, since it uses less digits than its factorization.

18791616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1121 (or 1111 counting only the distinct ones).

The product of its digits is 18144, while the sum is 39.

The square root of 18791616 is about 4334.9297572164. The cubic root of 18791616 is about 265.8610463886.

The spelling of 18791616 in words is "eighteen million, seven hundred ninety-one thousand, six hundred sixteen".