77628820 has 12 divisors (see below), whose sum is σ = 163020564. Its totient is φ = 31051520.

The previous prime is 77628767. The next prime is 77628823. The reversal of 77628820 is 2882677.

It can be written as a sum of positive squares in 2 ways, for example, as 43007364 + 34621456 = 6558^2 + 5884^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77628823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1940701 + ... + 1940740.

It is an arithmetic number, because the mean of its divisors is an integer number (13585047).

Almost surely, 2^77628820 is an apocalyptic number.

It is an amenable number.

77628820 is an abundant number, since it is smaller than the sum of its proper divisors (85391744).

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

77628820 is a wasteful number, since it uses less digits than its factorization.

77628820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3881450 (or 3881448 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 40.

The square root of 77628820 is about 8810.7218773492. The cubic root of 77628820 is about 426.5870443328.

The spelling of 77628820 in words is "seventy-seven million, six hundred twenty-eight thousand, eight hundred twenty".