20720010171611 has 4 divisors (see below), whose sum is σ = 20720156269224. Its totient is φ = 20719864074000.

The previous prime is 20720010171607. The next prime is 20720010171613. The reversal of 20720010171611 is 11617101002702.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20720010171611 - 2² = 20720010171607 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20720010171613) 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, 72835865 + ... + 73119786.

It is an arithmetic number, because the mean of its divisors is an integer number (5180039067306).

Almost surely, 2^{20720010171611} is an apocalyptic number.

20720010171611 is a deficient number, since it is larger than the sum of its proper divisors (146097613).

20720010171611 is a wasteful number, since it uses less digits than its factorization.

20720010171611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146097612.

The product of its (nonzero) digits is 1176, while the sum is 29.

The spelling of 20720010171611 in words is "twenty trillion, seven hundred twenty billion, ten million, one hundred seventy-one thousand, six hundred eleven".