71565731 has 2 divisors, whose sum is σ = 71565732. Its totient is φ = 71565730.

The previous prime is 71565721. The next prime is 71565757. The reversal of 71565731 is 13756517.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 71565731 - 2⁶ = 71565667 is a prime.

It is a super-2 number, since 2×71565731² = 10243307707128722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 71565691 and 71565700.

It is not a weakly prime, because it can be changed into another prime (71565721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35782865 + 35782866.

It is an arithmetic number, because the mean of its divisors is an integer number (35782866).

Almost surely, 2^71565731 is an apocalyptic number.

71565731 is a deficient number, since it is larger than the sum of its proper divisors (1).

71565731 is an equidigital number, since it uses as much as digits as its factorization.

71565731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22050, while the sum is 35.

The square root of 71565731 is about 8459.6531252765. The cubic root of 71565731 is about 415.1786737282.

The spelling of 71565731 in words is "seventy-one million, five hundred sixty-five thousand, seven hundred thirty-one".