991809460 has 24 divisors (see below), whose sum is σ = 2086630560. Its totient is φ = 395994144.

The previous prime is 991809439. The next prime is 991809487. The reversal of 991809460 is 64908199.

It is a self number, because there is not a number n which added to its sum of digits gives 991809460.

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 in 7 ways as a sum of consecutive naturals, for example, 34390 + ... + 56269.

It is an arithmetic number, because the mean of its divisors is an integer number (86942940).

Almost surely, 2^991809460 is an apocalyptic number.

It is an amenable number.

991809460 is an abundant number, since it is smaller than the sum of its proper divisors (1094821100).

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

991809460 is a wasteful number, since it uses less digits than its factorization.

991809460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91215 (or 91213 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 46.

The square root of 991809460 is about 31493.0065252589. The cubic root of 991809460 is about 997.2623320134.

The spelling of 991809460 in words is "nine hundred ninety-one million, eight hundred nine thousand, four hundred sixty".