79215943861 has 4 divisors (see below), whose sum is σ = 79224180300. Its totient is φ = 79207707424.

The previous prime is 79215943843. The next prime is 79215943871. The reversal of 79215943861 is 16834951297.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 58066058961 + 21149884900 = 240969^2 + 145430^2 .

It is a cyclic number.

It is not a de Polignac number, because 79215943861 - 2⁷ = 79215943733 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 (79215943871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4103776 + ... + 4123033.

It is an arithmetic number, because the mean of its divisors is an integer number (19806045075).

Almost surely, 2^79215943861 is an apocalyptic number.

It is an amenable number.

79215943861 is a deficient number, since it is larger than the sum of its proper divisors (8236439).

79215943861 is an equidigital number, since it uses as much as digits as its factorization.

79215943861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8236438.

The product of its digits is 3265920, while the sum is 55.

The spelling of 79215943861 in words is "seventy-nine billion, two hundred fifteen million, nine hundred forty-three thousand, eight hundred sixty-one".