21988075171 has 2 divisors, whose sum is σ = 21988075172. Its totient is φ = 21988075170.

The previous prime is 21988075169. The next prime is 21988075231. The reversal of 21988075171 is 17157088912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21988075171 - 2¹ = 21988075169 is a prime.

Together with 21988075169, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21988675171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10994037585 + 10994037586.

It is an arithmetic number, because the mean of its divisors is an integer number (10994037586).

Almost surely, 2^21988075171 is an apocalyptic number.

21988075171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21988075171 is an equidigital number, since it uses as much as digits as its factorization.

21988075171 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 282240, while the sum is 49.

The spelling of 21988075171 in words is "twenty-one billion, nine hundred eighty-eight million, seventy-five thousand, one hundred seventy-one".