71820079129109 has 2 divisors, whose sum is σ = 71820079129110. Its totient is φ = 71820079129108.

The previous prime is 71820079129061. The next prime is 71820079129147. The reversal of 71820079129109 is 90192197002817.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39160248574225 + 32659830554884 = 6257815^2 + 5714878^2 .

It is a cyclic number.

It is not a de Polignac number, because 71820079129109 - 2¹² = 71820079125013 is a prime.

It is a super-2 number, since 2×71820079129109² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71820079122109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35910039564554 + 35910039564555.

It is an arithmetic number, because the mean of its divisors is an integer number (35910039564555).

Almost surely, 2^{71820079129109} is an apocalyptic number.

It is an amenable number.

71820079129109 is a deficient number, since it is larger than the sum of its proper divisors (1).

71820079129109 is an equidigital number, since it uses as much as digits as its factorization.

71820079129109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1143072, while the sum is 56.

The spelling of 71820079129109 in words is "seventy-one trillion, eight hundred twenty billion, seventy-nine million, one hundred twenty-nine thousand, one hundred nine".