6626621 has 2 divisors, whose sum is σ = 6626622. Its totient is φ = 6626620.

The previous prime is 6626603. The next prime is 6626623. The reversal of 6626621 is 1266266.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6528025 + 98596 = 2555^2 + 314^2 .

It is a cyclic number.

It is not a de Polignac number, because 6626621 - 2¹⁴ = 6610237 is a prime.

Together with 6626623, it forms a pair of twin primes.

It is a Chen prime.

It is a pancake number, because a pancake can be divided into 6626621 parts by 3640 straight cuts.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6626623) 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 as a sum of consecutive naturals, namely, 3313310 + 3313311.

It is an arithmetic number, because the mean of its divisors is an integer number (3313311).

Almost surely, 2^6626621 is an apocalyptic number.

It is an amenable number.

6626621 is a deficient number, since it is larger than the sum of its proper divisors (1).

6626621 is an equidigital number, since it uses as much as digits as its factorization.

6626621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 29.

The square root of 6626621 is about 2574.2224068639. Note that the first 3 decimals coincide. The cubic root of 6626621 is about 187.8296045479.

The spelling of 6626621 in words is "six million, six hundred twenty-six thousand, six hundred twenty-one".