6979921 has 4 divisors (see below), whose sum is σ = 7516852. Its totient is φ = 6442992.

The previous prime is 6979919. The next prime is 6979937. The reversal of 6979921 is 1299796.

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 4157521 + 2822400 = 2039^2 + 1680^2 .

It is a cyclic number.

It is not a de Polignac number, because 6979921 - 2¹ = 6979919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6979901) 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, 268446 + ... + 268471.

It is an arithmetic number, because the mean of its divisors is an integer number (1879213).

Almost surely, 2^6979921 is an apocalyptic number.

It is an amenable number.

6979921 is a deficient number, since it is larger than the sum of its proper divisors (536931).

6979921 is a wasteful number, since it uses less digits than its factorization.

6979921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 536930.

The product of its digits is 61236, while the sum is 43.

The square root of 6979921 is about 2641.9540117118. The cubic root of 6979921 is about 191.1100395674.

The spelling of 6979921 in words is "six million, nine hundred seventy-nine thousand, nine hundred twenty-one".