79891906 has 4 divisors (see below), whose sum is σ = 119837862. Its totient is φ = 39945952.

The previous prime is 79891901. The next prime is 79891913. The reversal of 79891906 is 60919897.

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., 72948681 + 6943225 = 8541^2 + 2635^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 79891906.

It is not an unprimeable number, because it can be changed into a prime (79891901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19972975 + ... + 19972978.

Almost surely, 2^79891906 is an apocalyptic number.

79891906 is a deficient number, since it is larger than the sum of its proper divisors (39945956).

79891906 is a wasteful number, since it uses less digits than its factorization.

79891906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39945955.

The product of its (nonzero) digits is 244944, while the sum is 49.

The square root of 79891906 is about 8938.2272291546. The cubic root of 79891906 is about 430.6927826480.

The spelling of 79891906 in words is "seventy-nine million, eight hundred ninety-one thousand, nine hundred six".