78713666 has 4 divisors (see below), whose sum is σ = 118070502. Its totient is φ = 39356832.

The previous prime is 78713629. The next prime is 78713671. The reversal of 78713666 is 66631787.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 68973025 + 9740641 = 8305^2 + 3121^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19678415 + ... + 19678418.

Almost surely, 2^78713666 is an apocalyptic number.

78713666 is a deficient number, since it is larger than the sum of its proper divisors (39356836).

78713666 is a wasteful number, since it uses less digits than its factorization.

78713666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39356835.

The product of its digits is 254016, while the sum is 44.

The square root of 78713666 is about 8872.0722494804. The cubic root of 78713666 is about 428.5650128034.

The spelling of 78713666 in words is "seventy-eight million, seven hundred thirteen thousand, six hundred sixty-six".