71211735521 has 2 divisors, whose sum is σ = 71211735522. Its totient is φ = 71211735520.

The previous prime is 71211735487. The next prime is 71211735533. The reversal of 71211735521 is 12553711217.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69569865121 + 1641870400 = 263761^2 + 40520^2 .

It is a cyclic number.

It is not a de Polignac number, because 71211735521 - 2³⁰ = 70137993697 is a prime.

It is a super-2 number, since 2×71211735521² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (71211735541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35605867760 + 35605867761.

It is an arithmetic number, because the mean of its divisors is an integer number (35605867761).

Almost surely, 2^71211735521 is an apocalyptic number.

It is an amenable number.

71211735521 is a deficient number, since it is larger than the sum of its proper divisors (1).

71211735521 is an equidigital number, since it uses as much as digits as its factorization.

71211735521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14700, while the sum is 35.

The spelling of 71211735521 in words is "seventy-one billion, two hundred eleven million, seven hundred thirty-five thousand, five hundred twenty-one".