18442644 has 48 divisors (see below), whose sum is σ = 48470016. Its totient is φ = 5407200.

The previous prime is 18442639. The next prime is 18442663. The reversal of 18442644 is 44624481.

It is a super-2 number, since 2×18442644² = 680262235421472, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1839 + ... + 6345.

It is an arithmetic number, because the mean of its divisors is an integer number (1009792).

Almost surely, 2^18442644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18442644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24235008).

18442644 is an abundant number, since it is smaller than the sum of its proper divisors (30027372).

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

18442644 is a wasteful number, since it uses less digits than its factorization.

18442644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4556 (or 4554 counting only the distinct ones).

The product of its digits is 24576, while the sum is 33.

The square root of 18442644 is about 4294.4899580742. The cubic root of 18442644 is about 264.2050175137.

The spelling of 18442644 in words is "eighteen million, four hundred forty-two thousand, six hundred forty-four".