71548556221 has 2 divisors, whose sum is σ = 71548556222. Its totient is φ = 71548556220.

The previous prime is 71548556143. The next prime is 71548556237. The reversal of 71548556221 is 12265584517.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44095380121 + 27453176100 = 209989^2 + 165690^2 .

It is a cyclic number.

It is not a de Polignac number, because 71548556221 - 2¹¹ = 71548554173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71548556281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35774278110 + 35774278111.

It is an arithmetic number, because the mean of its divisors is an integer number (35774278111).

Almost surely, 2^71548556221 is an apocalyptic number.

It is an amenable number.

71548556221 is a deficient number, since it is larger than the sum of its proper divisors (1).

71548556221 is an equidigital number, since it uses as much as digits as its factorization.

71548556221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 672000, while the sum is 46.

The spelling of 71548556221 in words is "seventy-one billion, five hundred forty-eight million, five hundred fifty-six thousand, two hundred twenty-one".