77688720 has 200 divisors, whose sum is σ = 284475840. Its totient is φ = 19595520.

The previous prime is 77688713. The next prime is 77688761. The reversal of 77688720 is 2788677.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

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

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 122805 + ... + 123435.

Almost surely, 2^77688720 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 77688720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142237920).

77688720 is an abundant number, since it is smaller than the sum of its proper divisors (206787120).

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

77688720 is a wasteful number, since it uses less digits than its factorization.

77688720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 675 (or 660 counting only the distinct ones).

The product of its (nonzero) digits is 263424, while the sum is 45.

The square root of 77688720 is about 8814.1204893058. The cubic root of 77688720 is about 426.6967372470.

The spelling of 77688720 in words is "seventy-seven million, six hundred eighty-eight thousand, seven hundred twenty".