77168640 has 128 divisors (see below), whose sum is σ = 248508720. Its totient is φ = 20447232.

The previous prime is 77168639. The next prime is 77168647. The reversal of 77168640 is 4686177.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77168647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 491442 + ... + 491598.

Almost surely, 2^77168640 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 77168640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124254360).

77168640 is an abundant number, since it is smaller than the sum of its proper divisors (171340080).

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

77168640 is an equidigital number, since it uses as much as digits as its factorization.

77168640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195 (or 167 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 39.

The square root of 77168640 is about 8784.5682876280. The cubic root of 77168640 is about 425.7424438875.

The spelling of 77168640 in words is "seventy-seven million, one hundred sixty-eight thousand, six hundred forty".