21112427171 has 4 divisors (see below), whose sum is σ = 23031738744. Its totient is φ = 19193115600.

The previous prime is 21112427137. The next prime is 21112427261. The reversal of 21112427171 is 17172421112.

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 21112427171 - 2²² = 21108232867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21112427101) 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, 959655770 + ... + 959655791.

It is an arithmetic number, because the mean of its divisors is an integer number (5757934686).

Almost surely, 2^21112427171 is an apocalyptic number.

21112427171 is a deficient number, since it is larger than the sum of its proper divisors (1919311573).

21112427171 is a wasteful number, since it uses less digits than its factorization.

21112427171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1919311572.

The product of its digits is 1568, while the sum is 29.

Adding to 21112427171 its reverse (17172421112), we get a palindrome (38284848283).

The spelling of 21112427171 in words is "twenty-one billion, one hundred twelve million, four hundred twenty-seven thousand, one hundred seventy-one".