71997971 has 2 divisors, whose sum is σ = 71997972. Its totient is φ = 71997970.

The previous prime is 71997949. The next prime is 71997977. The reversal of 71997971 is 17979917.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (17979917) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71997971 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (71997977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35998985 + 35998986.

It is an arithmetic number, because the mean of its divisors is an integer number (35998986).

Almost surely, 2^71997971 is an apocalyptic number.

71997971 is a deficient number, since it is larger than the sum of its proper divisors (1).

71997971 is an equidigital number, since it uses as much as digits as its factorization.

71997971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 250047, while the sum is 50.

The square root of 71997971 is about 8485.1618134247. The cubic root of 71997971 is about 416.0128567125.

The spelling of 71997971 in words is "seventy-one million, nine hundred ninety-seven thousand, nine hundred seventy-one".