6448442521 has 4 divisors (see below), whose sum is σ = 6448979044. Its totient is φ = 6447906000.

The previous prime is 6448442513. The next prime is 6448442549. The reversal of 6448442521 is 1252448446.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4236057225 + 2212385296 = 65085^2 + 47036^2 .

It is a cyclic number.

It is not a de Polignac number, because 6448442521 - 2³ = 6448442513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6448442501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 249810 + ... + 274411.

It is an arithmetic number, because the mean of its divisors is an integer number (1612244761).

Almost surely, 2^6448442521 is an apocalyptic number.

It is an amenable number.

6448442521 is a deficient number, since it is larger than the sum of its proper divisors (536523).

6448442521 is a wasteful number, since it uses less digits than its factorization.

6448442521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 536522.

The product of its digits is 245760, while the sum is 40.

The square root of 6448442521 is about 80302.1949949066. The cubic root of 6448442521 is about 1861.3081444898.

The spelling of 6448442521 in words is "six billion, four hundred forty-eight million, four hundred forty-two thousand, five hundred twenty-one".