71682781 has 2 divisors, whose sum is σ = 71682782. Its totient is φ = 71682780.

The previous prime is 71682773. The next prime is 71682797. The reversal of 71682781 is 18728617.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59814756 + 11868025 = 7734^2 + 3445^2 .

It is a cyclic number.

It is not a de Polignac number, because 71682781 - 2³ = 71682773 is a prime.

It is a super-2 number, since 2×71682781² = 10276842183787922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71682731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35841390 + 35841391.

It is an arithmetic number, because the mean of its divisors is an integer number (35841391).

Almost surely, 2^71682781 is an apocalyptic number.

It is an amenable number.

71682781 is a deficient number, since it is larger than the sum of its proper divisors (1).

71682781 is an equidigital number, since it uses as much as digits as its factorization.

71682781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37632, while the sum is 40.

The square root of 71682781 is about 8466.5684311886. The cubic root of 71682781 is about 415.4049002237.

The spelling of 71682781 in words is "seventy-one million, six hundred eighty-two thousand, seven hundred eighty-one".