215778228 has 96 divisors (see below), whose sum is σ = 544631808. Its totient is φ = 66355200.

The previous prime is 215778217. The next prime is 215778293. The reversal of 215778228 is 822877512.

215778228 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 215778228.

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, 839476 + ... + 839732.

It is an arithmetic number, because the mean of its divisors is an integer number (5673248).

Almost surely, 2^215778228 is an apocalyptic number.

It is an amenable number.

215778228 is an abundant number, since it is smaller than the sum of its proper divisors (328853580).

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

215778228 is a wasteful number, since it uses less digits than its factorization.

215778228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393 (or 391 counting only the distinct ones).

The product of its digits is 125440, while the sum is 42.

The square root of 215778228 is about 14689.3916824353. The cubic root of 215778228 is about 599.7945852382.

The spelling of 215778228 in words is "two hundred fifteen million, seven hundred seventy-eight thousand, two hundred twenty-eight".