20101221221171 has 4 divisors (see below), whose sum is σ = 20157213481200. Its totient is φ = 20045228961144.

The previous prime is 20101221221167. The next prime is 20101221221231. The reversal of 20101221221171 is 17112212210102.

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 20101221221171 - 2² = 20101221221167 is a prime.

It is a super-2 number, since 2×20101221221171² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20101221221111) 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, 27996129476 + ... + 27996130193.

It is an arithmetic number, because the mean of its divisors is an integer number (5039303370300).

Almost surely, 2^{20101221221171} is an apocalyptic number.

20101221221171 is a deficient number, since it is larger than the sum of its proper divisors (55992260029).

20101221221171 is an equidigital number, since it uses as much as digits as its factorization.

20101221221171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55992260028.

The product of its (nonzero) digits is 224, while the sum is 23.

Adding to 20101221221171 its reverse (17112212210102), we get a palindrome (37213433431273).

The spelling of 20101221221171 in words is "twenty trillion, one hundred one billion, two hundred twenty-one million, two hundred twenty-one thousand, one hundred seventy-one".