71173745221 has 2 divisors, whose sum is σ = 71173745222. Its totient is φ = 71173745220.

The previous prime is 71173745219. The next prime is 71173745243. The reversal of 71173745221 is 12254737117.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37129436100 + 34044309121 = 192690^2 + 184511^2 .

It is a cyclic number.

It is not a de Polignac number, because 71173745221 - 2¹ = 71173745219 is a prime.

Together with 71173745219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71173745261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35586872610 + 35586872611.

It is an arithmetic number, because the mean of its divisors is an integer number (35586872611).

Almost surely, 2^71173745221 is an apocalyptic number.

It is an amenable number.

71173745221 is a deficient number, since it is larger than the sum of its proper divisors (1).

71173745221 is an equidigital number, since it uses as much as digits as its factorization.

71173745221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82320, while the sum is 40.

The spelling of 71173745221 in words is "seventy-one billion, one hundred seventy-three million, seven hundred forty-five thousand, two hundred twenty-one".