28772226 has 64 divisors (see below), whose sum is σ = 73881600. Its totient is φ = 8129808.

The previous prime is 28772197. The next prime is 28772257. The reversal of 28772226 is 62227782.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38565 + ... + 39303.

It is an arithmetic number, because the mean of its divisors is an integer number (1154400).

Almost surely, 2^28772226 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28772226, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36940800).

28772226 is an abundant number, since it is smaller than the sum of its proper divisors (45109374).

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

28772226 is a wasteful number, since it uses less digits than its factorization.

28772226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 860 (or 854 counting only the distinct ones).

The product of its digits is 37632, while the sum is 36.

The square root of 28772226 is about 5363.9748321557. The cubic root of 28772226 is about 306.4252066445.

The spelling of 28772226 in words is "twenty-eight million, seven hundred seventy-two thousand, two hundred twenty-six".