71370781 has 2 divisors, whose sum is σ = 71370782. Its totient is φ = 71370780.

The previous prime is 71370763. The next prime is 71370797. The reversal of 71370781 is 18707317.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66683556 + 4687225 = 8166^2 + 2165^2 .

It is a cyclic number.

It is not a de Polignac number, because 71370781 - 2⁹ = 71370269 is a prime.

It is a super-2 number, since 2×71370781² = 10187576761099922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71370721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35685390 + 35685391.

It is an arithmetic number, because the mean of its divisors is an integer number (35685391).

Almost surely, 2^71370781 is an apocalyptic number.

It is an amenable number.

71370781 is a deficient number, since it is larger than the sum of its proper divisors (1).

71370781 is an equidigital number, since it uses as much as digits as its factorization.

71370781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8232, while the sum is 34.

The square root of 71370781 is about 8448.1229276094. The cubic root of 71370781 is about 414.8013390864.

The spelling of 71370781 in words is "seventy-one million, three hundred seventy thousand, seven hundred eighty-one".