78687688 has 8 divisors (see below), whose sum is σ = 147539430. Its totient is φ = 39343840.

The previous prime is 78687671. The next prime is 78687689. The reversal of 78687688 is 88678687.

It can be written as a sum of positive squares in only one way, i.e., 57729604 + 20958084 = 7598^2 + 4578^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (78687689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4917973 + ... + 4917988.

Almost surely, 2^78687688 is an apocalyptic number.

It is an amenable number.

78687688 is a deficient number, since it is larger than the sum of its proper divisors (68851742).

78687688 is a wasteful number, since it uses less digits than its factorization.

78687688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9835967 (or 9835963 counting only the distinct ones).

The product of its digits is 7225344, while the sum is 58.

The square root of 78687688 is about 8870.6080964047. The cubic root of 78687688 is about 428.5178609450.

Subtracting 78687688 from its reverse (88678687), we obtain a palindrome (9990999).

The spelling of 78687688 in words is "seventy-eight million, six hundred eighty-seven thousand, six hundred eighty-eight".