71284865 has 24 divisors (see below), whose sum is σ = 91686888. Its totient is φ = 53187840.

The previous prime is 71284847. The next prime is 71284867. The reversal of 71284865 is 56848217.

It can be written as a sum of positive squares in 4 ways, for example, as 6385729 + 64899136 = 2527^2 + 8056^2 .

It is not a de Polignac number, because 71284865 - 2¹⁰ = 71283841 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71284867) 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 in 23 ways as a sum of consecutive naturals, for example, 131495 + ... + 132035.

It is an arithmetic number, because the mean of its divisors is an integer number (3820287).

Almost surely, 2^71284865 is an apocalyptic number.

It is an amenable number.

71284865 is a deficient number, since it is larger than the sum of its proper divisors (20402023).

71284865 is a wasteful number, since it uses less digits than its factorization.

71284865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 657 (or 638 counting only the distinct ones).

The product of its digits is 107520, while the sum is 41.

The square root of 71284865 is about 8443.0364798454. The cubic root of 71284865 is about 414.6348265852.

The spelling of 71284865 in words is "seventy-one million, two hundred eighty-four thousand, eight hundred sixty-five".