71256226605521 has 2 divisors, whose sum is σ = 71256226605522. Its totient is φ = 71256226605520.

The previous prime is 71256226605493. The next prime is 71256226605547. The reversal of 71256226605521 is 12550662265217.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40542063580225 + 30714163025296 = 6367265^2 + 5542036^2 .

It is a cyclic number.

It is not a de Polignac number, because 71256226605521 - 2⁶ = 71256226605457 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 71256226605521.

It is not a weakly prime, because it can be changed into another prime (71256226685521) 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, 35628113302760 + 35628113302761.

It is an arithmetic number, because the mean of its divisors is an integer number (35628113302761).

Almost surely, 2^{71256226605521} is an apocalyptic number.

It is an amenable number.

71256226605521 is a deficient number, since it is larger than the sum of its proper divisors (1).

71256226605521 is an equidigital number, since it uses as much as digits as its factorization.

71256226605521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024000, while the sum is 50.

The spelling of 71256226605521 in words is "seventy-one trillion, two hundred fifty-six billion, two hundred twenty-six million, six hundred five thousand, five hundred twenty-one".