6921889 has 4 divisors (see below), whose sum is σ = 7454356. Its totient is φ = 6389424.

The previous prime is 6921883. The next prime is 6921917. The reversal of 6921889 is 9881296.

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 2117025 + 4804864 = 1455^2 + 2192^2 .

It is a cyclic number.

It is not a de Polignac number, because 6921889 - 2⁵ = 6921857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6921883) 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, 266214 + ... + 266239.

It is an arithmetic number, because the mean of its divisors is an integer number (1863589).

Almost surely, 2^6921889 is an apocalyptic number.

It is an amenable number.

6921889 is a deficient number, since it is larger than the sum of its proper divisors (532467).

6921889 is a wasteful number, since it uses less digits than its factorization.

6921889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532466.

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

The square root of 6921889 is about 2630.9483081201. The cubic root of 6921889 is about 190.5789267493.

The spelling of 6921889 in words is "six million, nine hundred twenty-one thousand, eight hundred eighty-nine".