7921279 has 4 divisors (see below), whose sum is σ = 7927920. Its totient is φ = 7914640.

The previous prime is 7921273. The next prime is 7921289. The reversal of 7921279 is 9721297.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 9721297 = 17 ⋅571841.

It is a cyclic number.

It is not a de Polignac number, because 7921279 - 2⁵ = 7921247 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 (7921273) 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, 982 + ... + 4099.

It is an arithmetic number, because the mean of its divisors is an integer number (1981980).

Almost surely, 2^7921279 is an apocalyptic number.

7921279 is a deficient number, since it is larger than the sum of its proper divisors (6641).

7921279 is a wasteful number, since it uses less digits than its factorization.

7921279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6640.

The product of its digits is 15876, while the sum is 37.

The square root of 7921279 is about 2814.4766831509. The cubic root of 7921279 is about 199.3418280913.

The spelling of 7921279 in words is "seven million, nine hundred twenty-one thousand, two hundred seventy-nine".