991291768 has 32 divisors (see below), whose sum is σ = 1906294320. Its totient is φ = 482976000.

The previous prime is 991291729. The next prime is 991291781. The reversal of 991291768 is 867192199.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 422278 + ... + 424618.

Almost surely, 2^991291768 is an apocalyptic number.

It is an amenable number.

991291768 is a deficient number, since it is larger than the sum of its proper divisors (915002552).

991291768 is a wasteful number, since it uses less digits than its factorization.

991291768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3679 (or 3675 counting only the distinct ones).

The product of its digits is 489888, while the sum is 52.

The square root of 991291768 is about 31484.7862943359. The cubic root of 991291768 is about 997.0887890753.

The spelling of 991291768 in words is "nine hundred ninety-one million, two hundred ninety-one thousand, seven hundred sixty-eight".