21608101169 has 4 divisors (see below), whose sum is σ = 21676265844. Its totient is φ = 21539936496.

The previous prime is 21608101159. The next prime is 21608101181. The reversal of 21608101169 is 96110180612.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6352887025 + 15255214144 = 79705^2 + 123512^2 .

It is a cyclic number.

It is not a de Polignac number, because 21608101169 - 2⁴ = 21608101153 is a prime.

It is a super-2 number, since 2×21608101169² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21608101159) 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, 34081862 + ... + 34082495.

It is an arithmetic number, because the mean of its divisors is an integer number (5419066461).

Almost surely, 2^21608101169 is an apocalyptic number.

It is an amenable number.

21608101169 is a deficient number, since it is larger than the sum of its proper divisors (68164675).

21608101169 is an equidigital number, since it uses as much as digits as its factorization.

21608101169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68164674.

The product of its (nonzero) digits is 5184, while the sum is 35.

The spelling of 21608101169 in words is "twenty-one billion, six hundred eight million, one hundred one thousand, one hundred sixty-nine".