101721220209 has 12 divisors (see below), whose sum is σ = 167920744576. Its totient is φ = 58126411512.

The previous prime is 101721220199. The next prime is 101721220217. The reversal of 101721220209 is 902022127101.

It is not a de Polignac number, because 101721220209 - 2⁴ = 101721220193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (101721220309) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 807311209 + ... + 807311334.

Almost surely, 2^101721220209 is an apocalyptic number.

It is an amenable number.

101721220209 is a deficient number, since it is larger than the sum of its proper divisors (66199524367).

101721220209 is a wasteful number, since it uses less digits than its factorization.

101721220209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1614622556 (or 1614622553 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The spelling of 101721220209 in words is "one hundred one billion, seven hundred twenty-one million, two hundred twenty thousand, two hundred nine".