212778228 has 24 divisors (see below), whose sum is σ = 534673888. Its totient is φ = 65470176.

The previous prime is 212778227. The next prime is 212778271. The reversal of 212778228 is 822877212.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212778227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 681826 + ... + 682137.

Almost surely, 2^212778228 is an apocalyptic number.

It is an amenable number.

212778228 is an abundant number, since it is smaller than the sum of its proper divisors (321895660).

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

212778228 is a wasteful number, since it uses less digits than its factorization.

212778228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1363983 (or 1363981 counting only the distinct ones).

The product of its digits is 50176, while the sum is 39.

The square root of 212778228 is about 14586.9197570975. The cubic root of 212778228 is about 597.0019219430.

The spelling of 212778228 in words is "two hundred twelve million, seven hundred seventy-eight thousand, two hundred twenty-eight".