79639121 has 4 divisors (see below), whose sum is σ = 79769652. Its totient is φ = 79508592.

The previous prime is 79639057. The next prime is 79639129. The reversal of 79639121 is 12193697.

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 20349121 + 59290000 = 4511^2 + 7700^2 .

It is a cyclic number.

It is not a de Polignac number, because 79639121 - 2⁶ = 79639057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79639129) 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, 64346 + ... + 65571.

It is an arithmetic number, because the mean of its divisors is an integer number (19942413).

Almost surely, 2^79639121 is an apocalyptic number.

It is an amenable number.

79639121 is a deficient number, since it is larger than the sum of its proper divisors (130531).

79639121 is a wasteful number, since it uses less digits than its factorization.

79639121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130530.

The product of its digits is 20412, while the sum is 38.

The square root of 79639121 is about 8924.0753582654. The cubic root of 79639121 is about 430.2380527913.

The spelling of 79639121 in words is "seventy-nine million, six hundred thirty-nine thousand, one hundred twenty-one".