20001720205 has 8 divisors (see below), whose sum is σ = 24512746752. Its totient is φ = 15660921168.

The previous prime is 20001720203. The next prime is 20001720229. The reversal of 20001720205 is 50202710002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20001720205 - 2¹ = 20001720203 is a prime.

It is a super-2 number, since 2×20001720205² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001720203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42556617 + ... + 42557086.

It is an arithmetic number, because the mean of its divisors is an integer number (3064093344).

Almost surely, 2^20001720205 is an apocalyptic number.

It is an amenable number.

20001720205 is a deficient number, since it is larger than the sum of its proper divisors (4511026547).

20001720205 is an equidigital number, since it uses as much as digits as its factorization.

20001720205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85113755.

The product of its (nonzero) digits is 280, while the sum is 19.

The spelling of 20001720205 in words is "twenty billion, one million, seven hundred twenty thousand, two hundred five".