991149784 has 16 divisors (see below), whose sum is σ = 1908633600. Its totient is φ = 482180832.

The previous prime is 991149779. The next prime is 991149811. The reversal of 991149784 is 487941199.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1673944 + ... + 1674535.

It is an arithmetic number, because the mean of its divisors is an integer number (119289600).

Almost surely, 2^991149784 is an apocalyptic number.

It is an amenable number.

991149784 is a deficient number, since it is larger than the sum of its proper divisors (917483816).

991149784 is a wasteful number, since it uses less digits than its factorization.

991149784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3348522 (or 3348518 counting only the distinct ones).

The product of its digits is 653184, while the sum is 52.

The square root of 991149784 is about 31482.5314102916. The cubic root of 991149784 is about 997.0411820307.

It can be divided in two parts, 9911 and 49784, that added together give a palindrome (59695).

The spelling of 991149784 in words is "nine hundred ninety-one million, one hundred forty-nine thousand, seven hundred eighty-four".