71581331 has 2 divisors, whose sum is σ = 71581332. Its totient is φ = 71581330.

The previous prime is 71581327. The next prime is 71581343. The reversal of 71581331 is 13318517.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 71581331 - 2² = 71581327 is a prime.

It is a super-2 number, since 2×71581331² = 10247773895463122, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 71581294 and 71581303.

It is not a weakly prime, because it can be changed into another prime (71581361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35790665 + 35790666.

It is an arithmetic number, because the mean of its divisors is an integer number (35790666).

Almost surely, 2^71581331 is an apocalyptic number.

71581331 is a deficient number, since it is larger than the sum of its proper divisors (1).

71581331 is an equidigital number, since it uses as much as digits as its factorization.

71581331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2520, while the sum is 29.

The square root of 71581331 is about 8460.5750986561. The cubic root of 71581331 is about 415.2088386162.

Adding to 71581331 its reverse (13318517), we get a palindrome (84899848).

The spelling of 71581331 in words is "seventy-one million, five hundred eighty-one thousand, three hundred thirty-one".