71945909398849 has 2 divisors, whose sum is σ = 71945909398850. Its totient is φ = 71945909398848.

The previous prime is 71945909398837. The next prime is 71945909398919. The reversal of 71945909398849 is 94889390954917.

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., 49206296678400 + 22739612720449 = 7014720^2 + 4768607^2 .

It is a cyclic number.

It is not a de Polignac number, because 71945909398849 - 2⁵ = 71945909398817 is a prime.

It is not a weakly prime, because it can be changed into another prime (71945909498849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35972954699424 + 35972954699425.

It is an arithmetic number, because the mean of its divisors is an integer number (35972954699425).

Almost surely, 2^{71945909398849} is an apocalyptic number.

It is an amenable number.

71945909398849 is a deficient number, since it is larger than the sum of its proper divisors (1).

71945909398849 is an equidigital number, since it uses as much as digits as its factorization.

71945909398849 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6348948480, while the sum is 85.

The spelling of 71945909398849 in words is "seventy-one trillion, nine hundred forty-five billion, nine hundred nine million, three hundred ninety-eight thousand, eight hundred forty-nine".