31581873993 has 4 divisors (see below), whose sum is σ = 42109165328. Its totient is φ = 21054582660.

The previous prime is 31581873943. The next prime is 31581873997. The reversal of 31581873993 is 39937818513.

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, and also an emirpimes, since its reverse is a distinct semiprime: 39937818513 = 3 ⋅13312606171.

It is not a de Polignac number, because 31581873993 - 2⁸ = 31581873737 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31581873997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5263645663 + ... + 5263645668.

It is an arithmetic number, because the mean of its divisors is an integer number (10527291332).

Almost surely, 2^31581873993 is an apocalyptic number.

It is an amenable number.

31581873993 is a deficient number, since it is larger than the sum of its proper divisors (10527291335).

31581873993 is a wasteful number, since it uses less digits than its factorization.

31581873993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10527291334.

The product of its digits is 4898880, while the sum is 57.

The spelling of 31581873993 in words is "thirty-one billion, five hundred eighty-one million, eight hundred seventy-three thousand, nine hundred ninety-three".