71643307531 has 4 divisors (see below), whose sum is σ = 71668195200. Its totient is φ = 71618419864.

The previous prime is 71643307493. The next prime is 71643307583. The reversal of 71643307531 is 13570334617.

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

It is a cyclic number.

It is not a de Polignac number, because 71643307531 - 2¹⁵ = 71643274763 is a prime.

It is a super-2 number, since 2×71643307531² (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 (71643307831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12439516 + ... + 12445273.

It is an arithmetic number, because the mean of its divisors is an integer number (17917048800).

Almost surely, 2^71643307531 is an apocalyptic number.

71643307531 is a deficient number, since it is larger than the sum of its proper divisors (24887669).

71643307531 is a wasteful number, since it uses less digits than its factorization.

71643307531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24887668.

The product of its (nonzero) digits is 158760, while the sum is 40.

The spelling of 71643307531 in words is "seventy-one billion, six hundred forty-three million, three hundred seven thousand, five hundred thirty-one".