71911394569 has 27 divisors (see below), whose sum is σ = 86701683861. Its totient is φ = 59467826880.

The previous prime is 71911394567. The next prime is 71911394587. The reversal of 71911394569 is 96549311917.

The square root of 71911394569 is 268163.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 18615054969 + 53296339600 = 136437^2 + 230860^2 .

It is not a de Polignac number, because 71911394569 - 2¹ = 71911394567 is a prime.

It is a super-2 number, since 2×71911394569² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71911394567) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 54436429 + ... + 54437749.

Almost surely, 2^71911394569 is an apocalyptic number.

71911394569 is the 268163-rd square number.

71911394569 is the 134082-nd centered octagonal number.

It is an amenable number.

71911394569 is a deficient number, since it is larger than the sum of its proper divisors (14790289292).

71911394569 is an frugal number, since it uses more digits than its factorization.

71911394569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2714 (or 1357 counting only the distinct ones).

The product of its digits is 1837080, while the sum is 55.

The spelling of 71911394569 in words is "seventy-one billion, nine hundred eleven million, three hundred ninety-four thousand, five hundred sixty-nine".