18078444 has 24 divisors (see below), whose sum is σ = 46870320. Its totient is φ = 6026112.

The previous prime is 18078433. The next prime is 18078449. The reversal of 18078444 is 44487081.

It is a happy number.

It is a super-2 number, since 2×18078444² = 653660274922272, which contains 22 as substring.

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 = 18078399 and 18078408.

It is not an unprimeable number, because it can be changed into a prime (18078449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83589 + ... + 83804.

It is an arithmetic number, because the mean of its divisors is an integer number (1952930).

Almost surely, 2^18078444 is an apocalyptic number.

It is an amenable number.

18078444 is an abundant number, since it is smaller than the sum of its proper divisors (28791876).

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

18078444 is a wasteful number, since it uses less digits than its factorization.

18078444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167406 (or 167398 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 36.

The square root of 18078444 is about 4251.8753509481. The cubic root of 18078444 is about 262.4542940831.

The spelling of 18078444 in words is "eighteen million, seventy-eight thousand, four hundred forty-four".