79778109 has 4 divisors (see below), whose sum is σ = 106370816. Its totient is φ = 53185404.

The previous prime is 79778107. The next prime is 79778143. The reversal of 79778109 is 90187797.

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 not a de Polignac number, because 79778109 - 2¹ = 79778107 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 (79778107) 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, 13296349 + ... + 13296354.

It is an arithmetic number, because the mean of its divisors is an integer number (26592704).

Almost surely, 2^79778109 is an apocalyptic number.

It is an amenable number.

79778109 is a deficient number, since it is larger than the sum of its proper divisors (26592707).

79778109 is a wasteful number, since it uses less digits than its factorization.

79778109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26592706.

The product of its (nonzero) digits is 222264, while the sum is 48.

The square root of 79778109 is about 8931.8592129523. The cubic root of 79778109 is about 430.4881943989.

The spelling of 79778109 in words is "seventy-nine million, seven hundred seventy-eight thousand, one hundred nine".