6620981 has 2 divisors, whose sum is σ = 6620982. Its totient is φ = 6620980.

The previous prime is 6620953. The next prime is 6621029. The reversal of 6620981 is 1890266.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3964081 + 2656900 = 1991^2 + 1630^2 .

It is a cyclic number.

It is not a de Polignac number, because 6620981 - 2¹⁸ = 6358837 is a prime.

It is a super-2 number, since 2×6620981² = 87674778804722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6620951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3310490 + 3310491.

It is an arithmetic number, because the mean of its divisors is an integer number (3310491).

Almost surely, 2^6620981 is an apocalyptic number.

It is an amenable number.

6620981 is a deficient number, since it is larger than the sum of its proper divisors (1).

6620981 is an equidigital number, since it uses as much as digits as its factorization.

6620981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 6620981 is about 2573.1266972304. The cubic root of 6620981 is about 187.7763013810.

The spelling of 6620981 in words is "six million, six hundred twenty thousand, nine hundred eighty-one".