6445921 has 8 divisors (see below), whose sum is σ = 6854400. Its totient is φ = 6044400.

The previous prime is 6445919. The next prime is 6445937. The reversal of 6445921 is 1295446.

6445921 = 179² + 180² + ... + 292².

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6445921 - 2¹ = 6445919 is a prime.

It is a Duffinian number.

6445921 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6445951) 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 in 7 ways as a sum of consecutive naturals, for example, 240 + ... + 3598.

It is an arithmetic number, because the mean of its divisors is an integer number (856800).

Almost surely, 2^6445921 is an apocalyptic number.

It is an amenable number.

6445921 is a deficient number, since it is larger than the sum of its proper divisors (408479).

6445921 is a wasteful number, since it uses less digits than its factorization.

6445921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3479.

The product of its digits is 8640, while the sum is 31.

The square root of 6445921 is about 2538.8818404959. The cubic root of 6445921 is about 186.1065505050.

The spelling of 6445921 in words is "six million, four hundred forty-five thousand, nine hundred twenty-one".