77706720 has 288 divisors, whose sum is σ = 326918592. Its totient is φ = 16367616.

The previous prime is 77706709. The next prime is 77706743. The reversal of 77706720 is 2760777.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 130744 + ... + 131336.

It is an arithmetic number, because the mean of its divisors is an integer number (1135134).

Almost surely, 2^77706720 is an apocalyptic number.

77706720 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77706720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (163459296).

77706720 is an abundant number, since it is smaller than the sum of its proper divisors (249211872).

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

77706720 is a wasteful number, since it uses less digits than its factorization.

77706720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 634 (or 623 counting only the distinct ones).

The product of its (nonzero) digits is 28812, while the sum is 36.

The square root of 77706720 is about 8815.1415190001. The cubic root of 77706720 is about 426.7296890413.

The spelling of 77706720 in words is "seventy-seven million, seven hundred six thousand, seven hundred twenty".