71531992321 has 4 divisors (see below), whose sum is σ = 71831289600. Its totient is φ = 71232695044.

The previous prime is 71531992249. The next prime is 71531992331. The reversal of 71531992321 is 12329913517.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 71531992321 - 2¹¹ = 71531990273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71531992331) 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, 149648281 + ... + 149648758.

It is an arithmetic number, because the mean of its divisors is an integer number (17957822400).

Almost surely, 2^71531992321 is an apocalyptic number.

It is an amenable number.

71531992321 is a deficient number, since it is larger than the sum of its proper divisors (299297279).

71531992321 is a wasteful number, since it uses less digits than its factorization.

71531992321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299297278.

The product of its digits is 102060, while the sum is 43.

The spelling of 71531992321 in words is "seventy-one billion, five hundred thirty-one million, nine hundred ninety-two thousand, three hundred twenty-one".