6401669 has 2 divisors, whose sum is σ = 6401670. Its totient is φ = 6401668.

The previous prime is 6401621. The next prime is 6401687. The reversal of 6401669 is 9661046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4264225 + 2137444 = 2065^2 + 1462^2 .

It is a cyclic number.

It is not a de Polignac number, because 6401669 - 2⁸ = 6401413 is a prime.

It is a super-2 number, since 2×6401669² = 81962731971122, 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 (6401609) 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, 3200834 + 3200835.

It is an arithmetic number, because the mean of its divisors is an integer number (3200835).

Almost surely, 2^6401669 is an apocalyptic number.

It is an amenable number.

6401669 is a deficient number, since it is larger than the sum of its proper divisors (1).

6401669 is an equidigital number, since it uses as much as digits as its factorization.

6401669 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 6401669 is about 2530.1519717203. The cubic root of 6401669 is about 185.6796911330.

The spelling of 6401669 in words is "six million, four hundred one thousand, six hundred sixty-nine".