79991201221 has 4 divisors (see below), whose sum is σ = 79992813600. Its totient is φ = 79989588844.

The previous prime is 79991201219. The next prime is 79991201273. The reversal of 79991201221 is 12210219997.

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 79991201221 - 2¹ = 79991201219 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 (79991201321) 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, 729331 + ... + 831808.

It is an arithmetic number, because the mean of its divisors is an integer number (19998203400).

Almost surely, 2^79991201221 is an apocalyptic number.

It is an amenable number.

79991201221 is a deficient number, since it is larger than the sum of its proper divisors (1612379).

79991201221 is a wasteful number, since it uses less digits than its factorization.

79991201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1612378.

The product of its (nonzero) digits is 40824, while the sum is 43.

The spelling of 79991201221 in words is "seventy-nine billion, nine hundred ninety-one million, two hundred one thousand, two hundred twenty-one".