991409140 has 24 divisors (see below), whose sum is σ = 2149120512. Its totient is φ = 383771040.

The previous prime is 991409137. The next prime is 991409141. The reversal of 991409140 is 41904199.

It is a self number, because there is not a number n which added to its sum of digits gives 991409140.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991409141) by changing a digit.

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, 798904 + ... + 800143.

It is an arithmetic number, because the mean of its divisors is an integer number (89546688).

Almost surely, 2^991409140 is an apocalyptic number.

It is an amenable number.

991409140 is an abundant number, since it is smaller than the sum of its proper divisors (1157711372).

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

991409140 is a wasteful number, since it uses less digits than its factorization.

991409140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1599087 (or 1599085 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 991409140 is about 31486.6501870237. The cubic root of 991409140 is about 997.1281403173.

The spelling of 991409140 in words is "nine hundred ninety-one million, four hundred nine thousand, one hundred forty".