71216813 has 2 divisors, whose sum is σ = 71216814. Its totient is φ = 71216812.

The previous prime is 71216777. The next prime is 71216839. The reversal of 71216813 is 31861217.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70778569 + 438244 = 8413^2 + 662^2 .

It is a cyclic number.

It is not a de Polignac number, because 71216813 - 2¹⁰ = 71215789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71216843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35608406 + 35608407.

It is an arithmetic number, because the mean of its divisors is an integer number (35608407).

Almost surely, 2^71216813 is an apocalyptic number.

It is an amenable number.

71216813 is a deficient number, since it is larger than the sum of its proper divisors (1).

71216813 is an equidigital number, since it uses as much as digits as its factorization.

71216813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 29.

The square root of 71216813 is about 8439.0054508810. The cubic root of 71216813 is about 414.5028410508.

The spelling of 71216813 in words is "seventy-one million, two hundred sixteen thousand, eight hundred thirteen".