79891905 has 8 divisors (see below), whose sum is σ = 127827072. Its totient is φ = 42609008.

The previous prime is 79891901. The next prime is 79891913. The reversal of 79891905 is 50919897.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 79891905 - 2² = 79891901 is a prime.

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 in 7 ways as a sum of consecutive naturals, for example, 2663049 + ... + 2663078.

It is an arithmetic number, because the mean of its divisors is an integer number (15978384).

Almost surely, 2^79891905 is an apocalyptic number.

It is an amenable number.

79891905 is a deficient number, since it is larger than the sum of its proper divisors (47935167).

79891905 is a wasteful number, since it uses less digits than its factorization.

79891905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5326135.

The product of its (nonzero) digits is 204120, while the sum is 48.

The square root of 79891905 is about 8938.2271732151. The cubic root of 79891905 is about 430.6927808510.

The spelling of 79891905 in words is "seventy-nine million, eight hundred ninety-one thousand, nine hundred five".