18616428 has 72 divisors (see below), whose sum is σ = 52481520. Its totient is φ = 5529600.

The previous prime is 18616417. The next prime is 18616441. The reversal of 18616428 is 82461681.

18616428 is a `hidden beast` number, since 1 + 8 + 6 + 1 + 642 + 8 = 666.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 18616392 and 18616401.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10828 + ... + 12428.

It is an arithmetic number, because the mean of its divisors is an integer number (728910).

Almost surely, 2^18616428 is an apocalyptic number.

18616428 is a gapful number since it is divisible by the number (18) 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 18616428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26240760).

18616428 is an abundant number, since it is smaller than the sum of its proper divisors (33865092).

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

18616428 is a wasteful number, since it uses less digits than its factorization.

18616428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1647 (or 1642 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 18616428 is about 4314.6758858575. The cubic root of 18616428 is about 265.0322875101.

It can be divided in two parts, 18616 and 428, that added together give a square (19044 = 138²).

The spelling of 18616428 in words is "eighteen million, six hundred sixteen thousand, four hundred twenty-eight".