78991670 has 16 divisors (see below), whose sum is σ = 146028528. Its totient is φ = 30742560.

The previous prime is 78991669. The next prime is 78991691. The reversal of 78991670 is 7619987.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106376 + ... + 107115.

It is an arithmetic number, because the mean of its divisors is an integer number (9126783).

Almost surely, 2^78991670 is an apocalyptic number.

78991670 is a deficient number, since it is larger than the sum of its proper divisors (67036858).

78991670 is a wasteful number, since it uses less digits than its factorization.

78991670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213535.

The product of its (nonzero) digits is 190512, while the sum is 47.

The square root of 78991670 is about 8887.7258058516. The cubic root of 78991670 is about 429.0689608642.

The spelling of 78991670 in words is "seventy-eight million, nine hundred ninety-one thousand, six hundred seventy".