71755812578 has 4 divisors (see below), whose sum is σ = 107633718870. Its totient is φ = 35877906288.

The previous prime is 71755812577. The next prime is 71755812589. The reversal of 71755812578 is 87521855717.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 71648834929 + 106977649 = 267673^2 + 10343^2 .

It is a super-3 number, since 3×71755812578³ (a number of 34 digits) contains 333 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (71755812577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 17938953143 + ... + 17938953146.

Almost surely, 2^71755812578 is an apocalyptic number.

71755812578 is a deficient number, since it is larger than the sum of its proper divisors (35877906292).

71755812578 is a wasteful number, since it uses less digits than its factorization.

71755812578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35877906291.

The product of its digits is 5488000, while the sum is 56.

The spelling of 71755812578 in words is "seventy-one billion, seven hundred fifty-five million, eight hundred twelve thousand, five hundred seventy-eight".