825999991 has 8 divisors (see below), whose sum is σ = 853672064. Its totient is φ = 798392160.

The previous prime is 825999983. The next prime is 825999997. The reversal of 825999991 is 199999528.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 825999991 - 2³ = 825999983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (825999997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10825 + ... + 42061.

It is an arithmetic number, because the mean of its divisors is an integer number (106709008).

Almost surely, 2^825999991 is an apocalyptic number.

825999991 is a deficient number, since it is larger than the sum of its proper divisors (27672073).

825999991 is a wasteful number, since it uses less digits than its factorization.

825999991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32121.

The product of its digits is 4723920, while the sum is 61.

The square root of 825999991 is about 28740.2155698248. The cubic root of 825999991 is about 938.2675162101.

The spelling of 825999991 in words is "eight hundred twenty-five million, nine hundred ninety-nine thousand, nine hundred ninety-one".