71125981 has 2 divisors, whose sum is σ = 71125982. Its totient is φ = 71125980.

The previous prime is 71125973. The next prime is 71126023. The reversal of 71125981 is 18952117.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45024100 + 26101881 = 6710^2 + 5109^2 .

It is a cyclic number.

It is not a de Polignac number, because 71125981 - 2³ = 71125973 is a prime.

It is a super-2 number, since 2×71125981² = 10117810346424722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71125381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35562990 + 35562991.

It is an arithmetic number, because the mean of its divisors is an integer number (35562991).

Almost surely, 2^71125981 is an apocalyptic number.

It is an amenable number.

71125981 is a deficient number, since it is larger than the sum of its proper divisors (1).

71125981 is an equidigital number, since it uses as much as digits as its factorization.

71125981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 34.

The square root of 71125981 is about 8433.6220569812. The cubic root of 71125981 is about 414.3265430742.

The spelling of 71125981 in words is "seventy-one million, one hundred twenty-five thousand, nine hundred eighty-one".