1720281296221 has 4 divisors (see below), whose sum is σ = 1720292014944. Its totient is φ = 1720270577500.

The previous prime is 1720281296117. The next prime is 1720281296233. The reversal of 1720281296221 is 1226921820271.

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 1720281296221 - 2³⁹ = 1170525482333 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 (1720281296521) 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, 5114905 + ... + 5440846.

It is an arithmetic number, because the mean of its divisors is an integer number (430073003736).

Almost surely, 2^{1720281296221} is an apocalyptic number.

It is an amenable number.

1720281296221 is a deficient number, since it is larger than the sum of its proper divisors (10718723).

1720281296221 is a wasteful number, since it uses less digits than its factorization.

1720281296221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10718722.

The product of its (nonzero) digits is 96768, while the sum is 43.

The spelling of 1720281296221 in words is "one trillion, seven hundred twenty billion, two hundred eighty-one million, two hundred ninety-six thousand, two hundred twenty-one".