79191978 has 8 divisors (see below), whose sum is σ = 158383968. Its totient is φ = 26397324.

The previous prime is 79191977. The next prime is 79191991. The reversal of 79191978 is 87919197.

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

79191978 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 79191978.

It is not an unprimeable number, because it can be changed into a prime (79191971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6599326 + ... + 6599337.

It is an arithmetic number, because the mean of its divisors is an integer number (19797996).

Almost surely, 2^79191978 is an apocalyptic number.

79191978 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

79191978 is a wasteful number, since it uses less digits than its factorization.

79191978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13198668.

The product of its digits is 285768, while the sum is 51.

The square root of 79191978 is about 8898.9874704935. The cubic root of 79191978 is about 429.4313340950.

The spelling of 79191978 in words is "seventy-nine million, one hundred ninety-one thousand, nine hundred seventy-eight".