71381565 has 12 divisors (see below), whose sum is σ = 123728124. Its totient is φ = 38070144.

The previous prime is 71381509. The next prime is 71381617. The reversal of 71381565 is 56518317.

71381565 is a `hidden beast` number, since 7 + 13 + 81 + 565 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 30702681 + 40678884 = 5541^2 + 6378^2 .

It is not a de Polignac number, because 71381565 - 2⁹ = 71381053 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 793084 + ... + 793173.

It is an arithmetic number, because the mean of its divisors is an integer number (10310677).

Almost surely, 2^71381565 is an apocalyptic number.

It is an amenable number.

71381565 is a deficient number, since it is larger than the sum of its proper divisors (52346559).

71381565 is a wasteful number, since it uses less digits than its factorization.

71381565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1586268 (or 1586265 counting only the distinct ones).

The product of its digits is 25200, while the sum is 36.

The square root of 71381565 is about 8448.7611517902. The cubic root of 71381565 is about 414.8222299529.

The spelling of 71381565 in words is "seventy-one million, three hundred eighty-one thousand, five hundred sixty-five".