991344500 has 48 divisors (see below), whose sum is σ = 2176526352. Its totient is φ = 394444800.

The previous prime is 991344499. The next prime is 991344517. The reversal of 991344500 is 5443199.

It can be written as a sum of positive squares in 8 ways, for example, as 595652836 + 395691664 = 24406^2 + 19892^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91364 + ... + 101636.

It is an arithmetic number, because the mean of its divisors is an integer number (45344299).

Almost surely, 2^991344500 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 991344500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1088263176).

991344500 is an abundant number, since it is smaller than the sum of its proper divisors (1185181852).

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

991344500 is a wasteful number, since it uses less digits than its factorization.

991344500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10485 (or 10473 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 991344500 is about 31485.6237035254. The cubic root of 991344500 is about 997.1064688864.

Adding to 991344500 its reverse (5443199), we get a palindrome (996787699).

The spelling of 991344500 in words is "nine hundred ninety-one million, three hundred forty-four thousand, five hundred".