991230680 has 64 divisors (see below), whose sum is σ = 2474323200. Its totient is φ = 354328960.

The previous prime is 991230649. The next prime is 991230731. The reversal of 991230680 is 86032199.

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 15 ways as a sum of consecutive naturals, for example, 6869 + ... + 45051.

It is an arithmetic number, because the mean of its divisors is an integer number (38661300).

Almost surely, 2^991230680 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991230680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1237161600).

991230680 is an abundant number, since it is smaller than the sum of its proper divisors (1483092520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

991230680 is a wasteful number, since it uses less digits than its factorization.

991230680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38264 (or 38260 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 991230680 is about 31483.8161600528. The cubic root of 991230680 is about 997.0683069081.

The spelling of 991230680 in words is "nine hundred ninety-one million, two hundred thirty thousand, six hundred eighty".