6722521 has 8 divisors (see below), whose sum is σ = 7282184. Its totient is φ = 6168960.

The previous prime is 6722479. The next prime is 6722537. The reversal of 6722521 is 1252276.

It can be written as a sum of positive squares in 4 ways, for example, as 19600 + 6702921 = 140^2 + 2589^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6722521 - 2⁷ = 6722393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6722581) 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 7 ways as a sum of consecutive naturals, for example, 925 + ... + 3781.

It is an arithmetic number, because the mean of its divisors is an integer number (910273).

Almost surely, 2^6722521 is an apocalyptic number.

It is an amenable number.

6722521 is a deficient number, since it is larger than the sum of its proper divisors (559663).

6722521 is a wasteful number, since it uses less digits than its factorization.

6722521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3051.

The product of its digits is 1680, while the sum is 25.

The square root of 6722521 is about 2592.7824821994. The cubic root of 6722521 is about 188.7313540928.

Adding to 6722521 its reverse (1252276), we get a palindrome (7974797).

The spelling of 6722521 in words is "six million, seven hundred twenty-two thousand, five hundred twenty-one".