77928660 has 72 divisors (see below), whose sum is σ = 242793096. Its totient is φ = 20217600.

The previous prime is 77928649. The next prime is 77928661. The reversal of 77928660 is 6682977.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 32285124 + 45643536 = 5682^2 + 6756^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77928661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 810 + ... + 12510.

Almost surely, 2^77928660 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 77928660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121396548).

77928660 is an abundant number, since it is smaller than the sum of its proper divisors (164864436).

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

77928660 is a wasteful number, since it uses less digits than its factorization.

77928660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11753 (or 11748 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 45.

The square root of 77928660 is about 8827.7211102300. The cubic root of 77928660 is about 427.1355671245.

The spelling of 77928660 in words is "seventy-seven million, nine hundred twenty-eight thousand, six hundred sixty".