28155222 has 16 divisors (see below), whose sum is σ = 62567280. Its totient is φ = 9385056.

The previous prime is 28155199. The next prime is 28155227. The reversal of 28155222 is 22255182.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28155227) 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, 260643 + ... + 260750.

It is an arithmetic number, because the mean of its divisors is an integer number (3910455).

Almost surely, 2^28155222 is an apocalyptic number.

28155222 is an abundant number, since it is smaller than the sum of its proper divisors (34412058).

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

28155222 is a wasteful number, since it uses less digits than its factorization.

28155222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521404 (or 521398 counting only the distinct ones).

The product of its digits is 3200, while the sum is 27.

The square root of 28155222 is about 5306.1494513442. The cubic root of 28155222 is about 304.2189889683.

The spelling of 28155222 in words is "twenty-eight million, one hundred fifty-five thousand, two hundred twenty-two".