991231708 has 6 divisors (see below), whose sum is σ = 1734655496. Its totient is φ = 495615852.

The previous prime is 991231679. The next prime is 991231711. The reversal of 991231708 is 807132199.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 123903960 + ... + 123903967.

Almost surely, 2^991231708 is an apocalyptic number.

It is an amenable number.

991231708 is a deficient number, since it is larger than the sum of its proper divisors (743423788).

991231708 is a wasteful number, since it uses less digits than its factorization.

991231708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247807931 (or 247807929 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 40.

The square root of 991231708 is about 31483.8324858966. The cubic root of 991231708 is about 997.0686515927.

The spelling of 991231708 in words is "nine hundred ninety-one million, two hundred thirty-one thousand, seven hundred eight".