77792640 has 128 divisors (see below), whose sum is σ = 256158720. Its totient is φ = 20060160.

The previous prime is 77792599. The next prime is 77792653. The reversal of 77792640 is 4629777.

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

It is a junction number, because it is equal to n+sod(n) for n = 77792592 and 77792601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58867 + ... + 60173.

It is an arithmetic number, because the mean of its divisors is an integer number (2001240).

Almost surely, 2^77792640 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 77792640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128079360).

77792640 is an abundant number, since it is smaller than the sum of its proper divisors (178366080).

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

77792640 is a wasteful number, since it uses less digits than its factorization.

77792640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1360 (or 1348 counting only the distinct ones).

The product of its (nonzero) digits is 148176, while the sum is 42.

The square root of 77792640 is about 8820.0136054317. The cubic root of 77792640 is about 426.8869088625.

The spelling of 77792640 in words is "seventy-seven million, seven hundred ninety-two thousand, six hundred forty".