6563325721 has 4 divisors (see below), whose sum is σ = 6564618000. Its totient is φ = 6562033444.

The previous prime is 6563325707. The next prime is 6563325739. The reversal of 6563325721 is 1275233656.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6563325721 - 2¹¹ = 6563323673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6563325121) 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, 638491 + ... + 648688.

It is an arithmetic number, because the mean of its divisors is an integer number (1641154500).

Almost surely, 2^6563325721 is an apocalyptic number.

It is an amenable number.

6563325721 is a deficient number, since it is larger than the sum of its proper divisors (1292279).

6563325721 is a wasteful number, since it uses less digits than its factorization.

6563325721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1292278.

The product of its digits is 226800, while the sum is 40.

The square root of 6563325721 is about 81014.3550304512. The cubic root of 6563325721 is about 1872.2966169298.

The spelling of 6563325721 in words is "six billion, five hundred sixty-three million, three hundred twenty-five thousand, seven hundred twenty-one".