71856971 has 2 divisors, whose sum is σ = 71856972. Its totient is φ = 71856970.

The previous prime is 71856949. The next prime is 71856979. The reversal of 71856971 is 17965817.

It is a strong prime.

It is an emirp because it is prime and its reverse (17965817) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71856971 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (71856979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35928485 + 35928486.

It is an arithmetic number, because the mean of its divisors is an integer number (35928486).

Almost surely, 2^71856971 is an apocalyptic number.

71856971 is a deficient number, since it is larger than the sum of its proper divisors (1).

71856971 is an equidigital number, since it uses as much as digits as its factorization.

71856971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 105840, while the sum is 44.

The square root of 71856971 is about 8476.8491198086. The cubic root of 71856971 is about 415.7411076373.

It can be divided in two parts, 71856 and 971, that added together give a palindrome (72827).

The spelling of 71856971 in words is "seventy-one million, eight hundred fifty-six thousand, nine hundred seventy-one".