79778869 has 4 divisors (see below), whose sum is σ = 80388000. Its totient is φ = 79169740.

The previous prime is 79778863. The next prime is 79778899. The reversal of 79778869 is 96887797.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 79778869 - 2¹⁵ = 79746101 is a prime.

It is a super-2 number, since 2×79778869² = 12729335877838322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79778863) 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 3 ways as a sum of consecutive naturals, for example, 304369 + ... + 304630.

It is an arithmetic number, because the mean of its divisors is an integer number (20097000).

Almost surely, 2^79778869 is an apocalyptic number.

It is an amenable number.

79778869 is a deficient number, since it is larger than the sum of its proper divisors (609131).

79778869 is a wasteful number, since it uses less digits than its factorization.

79778869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 609130.

The product of its digits is 10668672, while the sum is 61.

The square root of 79778869 is about 8931.9017571847. The cubic root of 79778869 is about 430.4895613988.

The spelling of 79778869 in words is "seventy-nine million, seven hundred seventy-eight thousand, eight hundred sixty-nine".