6621731 has 2 divisors, whose sum is σ = 6621732. Its totient is φ = 6621730.

The previous prime is 6621707. The next prime is 6621749. The reversal of 6621731 is 1371266.

6621731 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6621731 - 2²² = 2427427 is a prime.

It is a super-2 number, since 2×6621731² = 87694642872722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6621731.

It is not a weakly prime, because it can be changed into another prime (6621751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3310865 + 3310866.

It is an arithmetic number, because the mean of its divisors is an integer number (3310866).

Almost surely, 2^6621731 is an apocalyptic number.

6621731 is a deficient number, since it is larger than the sum of its proper divisors (1).

6621731 is an equidigital number, since it uses as much as digits as its factorization.

6621731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1512, while the sum is 26.

The square root of 6621731 is about 2573.2724301947. The cubic root of 6621731 is about 187.7833913127.

Adding to 6621731 its reverse (1371266), we get a palindrome (7992997).

The spelling of 6621731 in words is "six million, six hundred twenty-one thousand, seven hundred thirty-one".