6622721 has 8 divisors (see below), whose sum is σ = 7712064. Its totient is φ = 5569200.

The previous prime is 6622711. The next prime is 6622729. The reversal of 6622721 is 1272266.

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

It is not a de Polignac number, because 6622721 - 2²² = 2428417 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 (6622729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8555 + ... + 9296.

It is an arithmetic number, because the mean of its divisors is an integer number (964008).

Almost surely, 2^6622721 is an apocalyptic number.

It is an amenable number.

6622721 is a deficient number, since it is larger than the sum of its proper divisors (1089343).

6622721 is a wasteful number, since it uses less digits than its factorization.

6622721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17911.

The product of its digits is 2016, while the sum is 26.

The square root of 6622721 is about 2573.4647850709. The cubic root of 6622721 is about 187.7927492028.

Adding to 6622721 its reverse (1272266), we get a palindrome (7894987).

The spelling of 6622721 in words is "six million, six hundred twenty-two thousand, seven hundred twenty-one".