991079825 has 12 divisors (see below), whose sum is σ = 1233142428. Its totient is φ = 790152000.

The previous prime is 991079819. The next prime is 991079833. The reversal of 991079825 is 528970199.

It is a happy number.

991079825 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 48344209 + 942735616 = 6953^2 + 30704^2 .

It is not a de Polignac number, because 991079825 - 2⁴ = 991079809 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 60326 + ... + 74975.

It is an arithmetic number, because the mean of its divisors is an integer number (102761869).

Almost surely, 2^991079825 is an apocalyptic number.

It is an amenable number.

991079825 is a deficient number, since it is larger than the sum of its proper divisors (242062603).

991079825 is a wasteful number, since it uses less digits than its factorization.

991079825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135604 (or 135599 counting only the distinct ones).

The product of its (nonzero) digits is 408240, while the sum is 50.

The square root of 991079825 is about 31481.4203142107. The cubic root of 991079825 is about 997.0177231999.

The spelling of 991079825 in words is "nine hundred ninety-one million, seventy-nine thousand, eight hundred twenty-five".