71221105565 has 16 divisors (see below), whose sum is σ = 88168862208. Its totient is φ = 55188340416.

The previous prime is 71221105523. The next prime is 71221105591. The reversal of 71221105565 is 56550112217.

It is not a de Polignac number, because 71221105565 - 2¹⁰ = 71221104541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 821927 + ... + 904436.

It is an arithmetic number, because the mean of its divisors is an integer number (5510553888).

Almost surely, 2^71221105565 is an apocalyptic number.

It is an amenable number.

71221105565 is a deficient number, since it is larger than the sum of its proper divisors (16947756643).

71221105565 is a wasteful number, since it uses less digits than its factorization.

71221105565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1726628.

The product of its (nonzero) digits is 21000, while the sum is 35.

The spelling of 71221105565 in words is "seventy-one billion, two hundred twenty-one million, one hundred five thousand, five hundred sixty-five".