6402661 has 2 divisors, whose sum is σ = 6402662. Its totient is φ = 6402660.

The previous prime is 6402653. The next prime is 6402701. The reversal of 6402661 is 1662046.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5712100 + 690561 = 2390^2 + 831^2 .

It is a cyclic number.

It is not a de Polignac number, because 6402661 - 2³ = 6402653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6402631) 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, 3201330 + 3201331.

It is an arithmetic number, because the mean of its divisors is an integer number (3201331).

Almost surely, 2^6402661 is an apocalyptic number.

It is an amenable number.

6402661 is a deficient number, since it is larger than the sum of its proper divisors (1).

6402661 is an equidigital number, since it uses as much as digits as its factorization.

6402661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 6402661 is about 2530.3479997818. The cubic root of 6402661 is about 185.6892815872.

The spelling of 6402661 in words is "six million, four hundred two thousand, six hundred sixty-one".