71541755221 has 2 divisors, whose sum is σ = 71541755222. Its totient is φ = 71541755220.

The previous prime is 71541755213. The next prime is 71541755251. The reversal of 71541755221 is 12255714517.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66622836996 + 4918918225 = 258114^2 + 70135^2 .

It is a cyclic number.

It is not a de Polignac number, because 71541755221 - 2³ = 71541755213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71541755251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35770877610 + 35770877611.

It is an arithmetic number, because the mean of its divisors is an integer number (35770877611).

Almost surely, 2^71541755221 is an apocalyptic number.

It is an amenable number.

71541755221 is a deficient number, since it is larger than the sum of its proper divisors (1).

71541755221 is an equidigital number, since it uses as much as digits as its factorization.

71541755221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 98000, while the sum is 40.

The spelling of 71541755221 in words is "seventy-one billion, five hundred forty-one million, seven hundred fifty-five thousand, two hundred twenty-one".