77813648 has 30 divisors (see below), whose sum is σ = 165719862. Its totient is φ = 35368960.

The previous prime is 77813639. The next prime is 77813707. The reversal of 77813648 is 84631877.

It can be written as a sum of positive squares in only one way, i.e., 57274624 + 20539024 = 7568^2 + 4532^2 .

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a junction number, because it is equal to n+sod(n) for n = 77813599 and 77813608.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18161 + ... + 22032.

Almost surely, 2^77813648 is an apocalyptic number.

It is an amenable number.

77813648 is an abundant number, since it is smaller than the sum of its proper divisors (87906214).

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

77813648 is a wasteful number, since it uses less digits than its factorization.

77813648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40223 (or 40206 counting only the distinct ones).

The product of its digits is 225792, while the sum is 44.

The square root of 77813648 is about 8821.2044529078. The cubic root of 77813648 is about 426.9253325190.

The spelling of 77813648 in words is "seventy-seven million, eight hundred thirteen thousand, six hundred forty-eight".