221676711721 has 4 divisors (see below), whose sum is σ = 221684097492. Its totient is φ = 221669325952.

The previous prime is 221676711719. The next prime is 221676711727. The reversal of 221676711721 is 127117676122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127117676122 = 2 ⋅63558838061.

It can be written as a sum of positive squares in 2 ways, for example, as 83934781225 + 137741930496 = 289715^2 + 371136^2 .

It is a cyclic number.

It is not a de Polignac number, because 221676711721 - 2¹ = 221676711719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221676711727) 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, 3647680 + ... + 3707953.

It is an arithmetic number, because the mean of its divisors is an integer number (55421024373).

Almost surely, 2^221676711721 is an apocalyptic number.

It is an amenable number.

221676711721 is a deficient number, since it is larger than the sum of its proper divisors (7385771).

221676711721 is an equidigital number, since it uses as much as digits as its factorization.

221676711721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7385770.

The product of its digits is 98784, while the sum is 43.

The spelling of 221676711721 in words is "two hundred twenty-one billion, six hundred seventy-six million, seven hundred eleven thousand, seven hundred twenty-one".