6921667 has 4 divisors (see below), whose sum is σ = 7082680. Its totient is φ = 6760656.

The previous prime is 6921653. The next prime is 6921671. The reversal of 6921667 is 7661296.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6921667 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6921617) 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, 80442 + ... + 80527.

It is an arithmetic number, because the mean of its divisors is an integer number (1770670).

Almost surely, 2^6921667 is an apocalyptic number.

6921667 is a deficient number, since it is larger than the sum of its proper divisors (161013).

6921667 is a wasteful number, since it uses less digits than its factorization.

6921667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161012.

The product of its digits is 27216, while the sum is 37.

The square root of 6921667 is about 2630.9061176712. The cubic root of 6921667 is about 190.5768893009.

It can be divided in two parts, 69 and 21667, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 6921667 in words is "six million, nine hundred twenty-one thousand, six hundred sixty-seven".