991563080 has 64 divisors (see below), whose sum is σ = 2368848240. Its totient is φ = 372252672.

The previous prime is 991563077. The next prime is 991563103. The reversal of 991563080 is 80365199.

It can be written as a sum of positive squares in 8 ways, for example, as 396886084 + 594676996 = 19922^2 + 24386^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 268124 + ... + 271796.

Almost surely, 2^991563080 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 991563080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1184424120).

991563080 is an abundant number, since it is smaller than the sum of its proper divisors (1377285160).

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

991563080 is a wasteful number, since it uses less digits than its factorization.

991563080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4098 (or 4094 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 41.

The square root of 991563080 is about 31489.0946202015. The cubic root of 991563080 is about 997.1797469835.

The spelling of 991563080 in words is "nine hundred ninety-one million, five hundred sixty-three thousand, eighty".