6722921 has 4 divisors (see below), whose sum is σ = 6879312. Its totient is φ = 6566532.

The previous prime is 6722909. The next prime is 6722929. The reversal of 6722921 is 1292276.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6722921 - 2⁶ = 6722857 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6722929) 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, 78131 + ... + 78216.

It is an arithmetic number, because the mean of its divisors is an integer number (1719828).

Almost surely, 2^6722921 is an apocalyptic number.

It is an amenable number.

6722921 is a deficient number, since it is larger than the sum of its proper divisors (156391).

6722921 is a wasteful number, since it uses less digits than its factorization.

6722921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156390.

The product of its digits is 3024, while the sum is 29.

The square root of 6722921 is about 2592.8596182593. The cubic root of 6722921 is about 188.7350972840.

The spelling of 6722921 in words is "six million, seven hundred twenty-two thousand, nine hundred twenty-one".