79887121 has 4 divisors (see below), whose sum is σ = 81241200. Its totient is φ = 78533044.

The previous prime is 79887113. The next prime is 79887127. The reversal of 79887121 is 12178897.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12178897 = 109 ⋅111733.

It is a cyclic number.

It is not a de Polignac number, because 79887121 - 2³ = 79887113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79887127) 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 3 ways as a sum of consecutive naturals, for example, 676951 + ... + 677068.

It is an arithmetic number, because the mean of its divisors is an integer number (20310300).

Almost surely, 2^79887121 is an apocalyptic number.

It is an amenable number.

79887121 is a deficient number, since it is larger than the sum of its proper divisors (1354079).

79887121 is a wasteful number, since it uses less digits than its factorization.

79887121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1354078.

The product of its digits is 56448, while the sum is 43.

The square root of 79887121 is about 8937.9595546187. The cubic root of 79887121 is about 430.6841839208.

It can be divided in two parts, 79887 and 121, that added together give a palindrome (80008).

The spelling of 79887121 in words is "seventy-nine million, eight hundred eighty-seven thousand, one hundred twenty-one".