71590781 has 2 divisors, whose sum is σ = 71590782. Its totient is φ = 71590780.

The previous prime is 71590769. The next prime is 71590801. The reversal of 71590781 is 18709517.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71554681 + 36100 = 8459^2 + 190^2 .

It is an emirp because it is prime and its reverse (18709517) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71590781 is a prime.

It is a super-2 number, since 2×71590781² = 10250479848379922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71590381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35795390 + 35795391.

It is an arithmetic number, because the mean of its divisors is an integer number (35795391).

Almost surely, 2^71590781 is an apocalyptic number.

It is an amenable number.

71590781 is a deficient number, since it is larger than the sum of its proper divisors (1).

71590781 is an equidigital number, since it uses as much as digits as its factorization.

71590781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17640, while the sum is 38.

The square root of 71590781 is about 8461.1335528994. The cubic root of 71590781 is about 415.2271094456.

The spelling of 71590781 in words is "seventy-one million, five hundred ninety thousand, seven hundred eighty-one".