31968509991 has 32 divisors (see below), whose sum is σ = 48568246272. Its totient is φ = 18514568160.

The previous prime is 31968509959. The next prime is 31968509999. The reversal of 31968509991 is 19990586913.

It is not a de Polignac number, because 31968509991 - 2⁵ = 31968509959 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31968509999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 787006 + ... + 826628.

It is an arithmetic number, because the mean of its divisors is an integer number (1517757696).

Almost surely, 2^31968509991 is an apocalyptic number.

31968509991 is a deficient number, since it is larger than the sum of its proper divisors (16599736281).

31968509991 is a wasteful number, since it uses less digits than its factorization.

31968509991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40723.

The product of its (nonzero) digits is 4723920, while the sum is 60.

The spelling of 31968509991 in words is "thirty-one billion, nine hundred sixty-eight million, five hundred nine thousand, nine hundred ninety-one".