71738860021 has 2 divisors, whose sum is σ = 71738860022. Its totient is φ = 71738860020.

The previous prime is 71738860007. The next prime is 71738860027. The reversal of 71738860021 is 12006883717.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59907947121 + 11830912900 = 244761^2 + 108770^2 .

It is a cyclic number.

It is not a de Polignac number, because 71738860021 - 2²¹ = 71736762869 is a prime.

It is a super-2 number, since 2×71738860021² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 71738860021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71738860027) 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, 35869430010 + 35869430011.

It is an arithmetic number, because the mean of its divisors is an integer number (35869430011).

Almost surely, 2^71738860021 is an apocalyptic number.

It is an amenable number.

71738860021 is a deficient number, since it is larger than the sum of its proper divisors (1).

71738860021 is an equidigital number, since it uses as much as digits as its factorization.

71738860021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112896, while the sum is 43.

The spelling of 71738860021 in words is "seventy-one billion, seven hundred thirty-eight million, eight hundred sixty thousand, twenty-one".