71393281 has 2 divisors, whose sum is σ = 71393282. Its totient is φ = 71393280.

The previous prime is 71393249. The next prime is 71393291. The reversal of 71393281 is 18239317.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62489025 + 8904256 = 7905^2 + 2984^2 .

It is a cyclic number.

It is not a de Polignac number, because 71393281 - 2⁵ = 71393249 is a prime.

It is a super-2 number, since 2×71393281² = 10194001143889922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (71393221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35696640 + 35696641.

It is an arithmetic number, because the mean of its divisors is an integer number (35696641).

Almost surely, 2^71393281 is an apocalyptic number.

It is an amenable number.

71393281 is a deficient number, since it is larger than the sum of its proper divisors (1).

71393281 is an equidigital number, since it uses as much as digits as its factorization.

71393281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 34.

The square root of 71393281 is about 8449.4544794324. The cubic root of 71393281 is about 414.8449239139.

The spelling of 71393281 in words is "seventy-one million, three hundred ninety-three thousand, two hundred eighty-one".