71535566813 has 8 divisors (see below), whose sum is σ = 71834274360. Its totient is φ = 71237017600.

The previous prime is 71535566803. The next prime is 71535566849. The reversal of 71535566813 is 31866553517.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 46570934809 + 24964632004 = 215803^2 + 158002^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 71535566813 - 2⁴ = 71535566797 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71535566803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 913553 + ... + 988761.

It is an arithmetic number, because the mean of its divisors is an integer number (8979284295).

Almost surely, 2^71535566813 is an apocalyptic number.

It is an amenable number.

71535566813 is a deficient number, since it is larger than the sum of its proper divisors (298707547).

71535566813 is a wasteful number, since it uses less digits than its factorization.

71535566813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79167.

The product of its digits is 2268000, while the sum is 50.

The spelling of 71535566813 in words is "seventy-one billion, five hundred thirty-five million, five hundred sixty-six thousand, eight hundred thirteen".