971233991 has 32 divisors (see below), whose sum is σ = 1249425408. Its totient is φ = 734469120.

The previous prime is 971233981. The next prime is 971234003. The reversal of 971233991 is 199332179.

It is not a de Polignac number, because 971233991 - 2¹⁴ = 971217607 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (971233981) 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 31 ways as a sum of consecutive naturals, for example, 181271 + ... + 186551.

It is an arithmetic number, because the mean of its divisors is an integer number (39044544).

Almost surely, 2^971233991 is an apocalyptic number.

971233991 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

971233991 is a deficient number, since it is larger than the sum of its proper divisors (278191417).

971233991 is a wasteful number, since it uses less digits than its factorization.

971233991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5391.

The product of its digits is 91854, while the sum is 44.

The square root of 971233991 is about 31164.6272398692. The cubic root of 971233991 is about 990.3178896160.

The spelling of 971233991 in words is "nine hundred seventy-one million, two hundred thirty-three thousand, nine hundred ninety-one".