721522067221 has 4 divisors (see below), whose sum is σ = 726712873600. Its totient is φ = 716331260844.

The previous prime is 721522067131. The next prime is 721522067239. The reversal of 721522067221 is 122760225127.

721522067221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 721522067221 - 2²⁷ = 721387849493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721522067291) 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, 2595402981 + ... + 2595403258.

It is an arithmetic number, because the mean of its divisors is an integer number (181678218400).

Almost surely, 2^721522067221 is an apocalyptic number.

It is an amenable number.

721522067221 is a deficient number, since it is larger than the sum of its proper divisors (5190806379).

721522067221 is a wasteful number, since it uses less digits than its factorization.

721522067221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5190806378.

The product of its (nonzero) digits is 47040, while the sum is 37.

The spelling of 721522067221 in words is "seven hundred twenty-one billion, five hundred twenty-two million, sixty-seven thousand, two hundred twenty-one".