78642866 has 16 divisors (see below), whose sum is σ = 119968128. Its totient is φ = 38656800.

The previous prime is 78642853. The next prime is 78642923. The reversal of 78642866 is 66824687.

It is a self number, because there is not a number n which added to its sum of digits gives 78642866.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73451 + ... + 74513.

It is an arithmetic number, because the mean of its divisors is an integer number (7498008).

Almost surely, 2^78642866 is an apocalyptic number.

78642866 is a deficient number, since it is larger than the sum of its proper divisors (41325262).

78642866 is a wasteful number, since it uses less digits than its factorization.

78642866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1657.

The product of its digits is 774144, while the sum is 47.

The square root of 78642866 is about 8868.0813031907. The cubic root of 78642866 is about 428.4364815234.

The spelling of 78642866 in words is "seventy-eight million, six hundred forty-two thousand, eight hundred sixty-six".