71218331 has 2 divisors, whose sum is σ = 71218332. Its totient is φ = 71218330.

The previous prime is 71218309. The next prime is 71218339. The reversal of 71218331 is 13381217.

It is a strong prime.

It is an emirp because it is prime and its reverse (13381217) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71218331 - 2⁶ = 71218267 is a prime.

It is a super-2 number, since 2×71218331² = 10144101340851122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71218331.

It is not a weakly prime, because it can be changed into another prime (71218339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35609165 + 35609166.

It is an arithmetic number, because the mean of its divisors is an integer number (35609166).

Almost surely, 2^71218331 is an apocalyptic number.

71218331 is a deficient number, since it is larger than the sum of its proper divisors (1).

71218331 is an equidigital number, since it uses as much as digits as its factorization.

71218331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 26.

The square root of 71218331 is about 8439.0953899100. The cubic root of 71218331 is about 414.5057860990.

Adding to 71218331 its reverse (13381217), we get a palindrome (84599548).

The spelling of 71218331 in words is "seventy-one million, two hundred eighteen thousand, three hundred thirty-one".