991110540 has 192 divisors, whose sum is σ = 3387654144. Its totient is φ = 211341312.

The previous prime is 991110539. The next prime is 991110541. The reversal of 991110540 is 45011199.

It is an interprime number because it is at equal distance from previous prime (991110539) and next prime (991110541).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 991110498 and 991110507.

It is not an unprimeable number, because it can be changed into a prime (991110541) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 906234 + ... + 907326.

It is an arithmetic number, because the mean of its divisors is an integer number (17644032).

Almost surely, 2^991110540 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 991110540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1693827072).

991110540 is an abundant number, since it is smaller than the sum of its proper divisors (2396543604).

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

991110540 is a wasteful number, since it uses less digits than its factorization.

991110540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1256 (or 1254 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 30.

The square root of 991110540 is about 31481.9081378496. The cubic root of 991110540 is about 997.0280227681.

The spelling of 991110540 in words is "nine hundred ninety-one million, one hundred ten thousand, five hundred forty".