79778663 has 4 divisors (see below), whose sum is σ = 83977560. Its totient is φ = 75579768.

The previous prime is 79778641. The next prime is 79778723. The reversal of 79778663 is 36687797.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 79778663 - 2¹⁴ = 79762279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79778063) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 2099420 + ... + 2099457.

It is an arithmetic number, because the mean of its divisors is an integer number (20994390).

Almost surely, 2^79778663 is an apocalyptic number.

79778663 is a deficient number, since it is larger than the sum of its proper divisors (4198897).

79778663 is a wasteful number, since it uses less digits than its factorization.

79778663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4198896.

The product of its digits is 2667168, while the sum is 53.

The square root of 79778663 is about 8931.8902254786. The cubic root of 79778663 is about 430.4891908707.

The spelling of 79778663 in words is "seventy-nine million, seven hundred seventy-eight thousand, six hundred sixty-three".