6446021 has 2 divisors, whose sum is σ = 6446022. Its totient is φ = 6446020.

The previous prime is 6446017. The next prime is 6446023. The reversal of 6446021 is 1206446.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5522500 + 923521 = 2350^2 + 961^2 .

It is a cyclic number.

It is not a de Polignac number, because 6446021 - 2² = 6446017 is a prime.

It is a Sophie Germain prime.

Together with 6446023, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6446023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3223010 + 3223011.

It is an arithmetic number, because the mean of its divisors is an integer number (3223011).

Almost surely, 2^6446021 is an apocalyptic number.

It is an amenable number.

6446021 is a deficient number, since it is larger than the sum of its proper divisors (1).

6446021 is an equidigital number, since it uses as much as digits as its factorization.

6446021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 6446021 is about 2538.9015341285. The cubic root of 6446021 is about 186.1075128996.

The spelling of 6446021 in words is "six million, four hundred forty-six thousand, twenty-one".