77766228 has 72 divisors (see below), whose sum is σ = 214905600. Its totient is φ = 23604480.

The previous prime is 77766187. The next prime is 77766233. The reversal of 77766228 is 82266777.

It is a happy number.

It is a congruent number.

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, 16923 + ... + 21021.

It is an arithmetic number, because the mean of its divisors is an integer number (2984800).

Almost surely, 2^77766228 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 77766228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107452800).

77766228 is an abundant number, since it is smaller than the sum of its proper divisors (137139372).

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

77766228 is a wasteful number, since it uses less digits than its factorization.

77766228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4157 (or 4152 counting only the distinct ones).

The product of its digits is 395136, while the sum is 45.

The square root of 77766228 is about 8818.5162017201. The cubic root of 77766228 is about 426.8385914668.

The spelling of 77766228 in words is "seventy-seven million, seven hundred sixty-six thousand, two hundred twenty-eight".