22278816 has 144 divisors (see below), whose sum is σ = 74378304. Its totient is φ = 6193152.

The previous prime is 22278793. The next prime is 22278827. The reversal of 22278816 is 61887222.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

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

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 23 ways as a sum of consecutive naturals, for example, 86560 + ... + 86816.

It is an arithmetic number, because the mean of its divisors is an integer number (516516).

Almost surely, 2^22278816 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 22278816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37189152).

22278816 is an abundant number, since it is smaller than the sum of its proper divisors (52099488).

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

22278816 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (22278815) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (323).

22278816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 312 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 22278816 is about 4720.0440675909. The cubic root of 22278816 is about 281.3826846531.

The spelling of 22278816 in words is "twenty-two million, two hundred seventy-eight thousand, eight hundred sixteen".