6889921 has 2 divisors, whose sum is σ = 6889922. Its totient is φ = 6889920.

The previous prime is 6889901. The next prime is 6889931. The reversal of 6889921 is 1299886.

It is a happy number.

6889921 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4456321 + 2433600 = 2111^2 + 1560^2 .

It is a cyclic number.

It is not a de Polignac number, because 6889921 - 2⁷ = 6889793 is a prime.

It is a super-2 number, since 2×6889921² = 94942022772482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6889901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3444960 + 3444961.

It is an arithmetic number, because the mean of its divisors is an integer number (3444961).

Almost surely, 2^6889921 is an apocalyptic number.

It is an amenable number.

6889921 is a deficient number, since it is larger than the sum of its proper divisors (1).

6889921 is an equidigital number, since it uses as much as digits as its factorization.

6889921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 43.

The square root of 6889921 is about 2624.8659013367. The cubic root of 6889921 is about 190.2850844979.

It can be divided in two parts, 688 and 9921, that added together give a square (10609 = 103²).

The spelling of 6889921 in words is "six million, eight hundred eighty-nine thousand, nine hundred twenty-one".