991925 has 12 divisors (see below), whose sum is σ = 1342176. Its totient is φ = 721200.

The previous prime is 991909. The next prime is 991927. The reversal of 991925 is 529199.

It is not a de Polignac number, because 991925 - 2⁴ = 991909 is a prime.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 991925.

It is not an unprimeable number, because it can be changed into a prime (991927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1529 + ... + 2078.

It is an arithmetic number, because the mean of its divisors is an integer number (111848).

2⁹⁹¹⁹²⁵ is an apocalyptic number.

It is an amenable number.

991925 is a deficient number, since it is larger than the sum of its proper divisors (350251).

991925 is a wasteful number, since it uses less digits than its factorization.

991925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3628 (or 3623 counting only the distinct ones).

The product of its digits is 7290, while the sum is 35.

The square root of 991925 is about 995.9543162214. The cubic root of 991925 is about 99.7301055586.

The spelling of 991925 in words is "nine hundred ninety-one thousand, nine hundred twenty-five".