79131377809 has 27 divisors (see below), whose sum is σ = 88168503241. Its totient is φ = 70967120840.

The previous prime is 79131377797. The next prime is 79131377833. The reversal of 79131377809 is 90877313197.

The square root of 79131377809 is 281303.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 79131377809 - 2¹⁹ = 79130853521 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 79131377809.

It is not an unprimeable number, because it can be changed into a prime (79131377849) 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 26 ways as a sum of consecutive naturals, for example, 331093512 + ... + 331093750.

Almost surely, 2^79131377809 is an apocalyptic number.

79131377809 is the 281303-rd square number.

79131377809 is the 140652-nd centered octagonal number.

It is an amenable number.

79131377809 is a deficient number, since it is larger than the sum of its proper divisors (9037125432).

79131377809 is an equidigital number, since it uses as much as digits as its factorization.

79131377809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 714 (or 357 counting only the distinct ones).

The product of its (nonzero) digits is 2000376, while the sum is 55.

The spelling of 79131377809 in words is "seventy-nine billion, one hundred thirty-one million, three hundred seventy-seven thousand, eight hundred nine".