21142405171 has 2 divisors, whose sum is σ = 21142405172. Its totient is φ = 21142405170.

The previous prime is 21142405153. The next prime is 21142405177. The reversal of 21142405171 is 17150424112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21142405171 - 2²⁹ = 20605534259 is a prime.

It is not a weakly prime, because it can be changed into another prime (21142405177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571202585 + 10571202586.

It is an arithmetic number, because the mean of its divisors is an integer number (10571202586).

Almost surely, 2^21142405171 is an apocalyptic number.

21142405171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142405171 is an equidigital number, since it uses as much as digits as its factorization.

21142405171 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2240, while the sum is 28.

Adding to 21142405171 its reverse (17150424112), we get a palindrome (38292829283).

The spelling of 21142405171 in words is "twenty-one billion, one hundred forty-two million, four hundred five thousand, one hundred seventy-one".