71985971 has 2 divisors, whose sum is σ = 71985972. Its totient is φ = 71985970.

The previous prime is 71985911. The next prime is 71985997. The reversal of 71985971 is 17958917.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71985971 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (71985911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35992985 + 35992986.

It is an arithmetic number, because the mean of its divisors is an integer number (35992986).

Almost surely, 2^71985971 is an apocalyptic number.

71985971 is a deficient number, since it is larger than the sum of its proper divisors (1).

71985971 is an equidigital number, since it uses as much as digits as its factorization.

71985971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 158760, while the sum is 47.

The square root of 71985971 is about 8484.4546672134. The cubic root of 71985971 is about 415.9897429516.

The spelling of 71985971 in words is "seventy-one million, nine hundred eighty-five thousand, nine hundred seventy-one".