826991 has 4 divisors (see below), whose sum is σ = 902184. Its totient is φ = 751800.

The previous prime is 826979. The next prime is 826997. The reversal of 826991 is 199628.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 826991 - 2⁶ = 826927 is a prime.

It is a super-2 number, since 2×826991² = 1367828228162, which contains 22 as substring.

It is a Duffinian 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 826991.

It is not an unprimeable number, because it can be changed into a prime (826997) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 37580 + ... + 37601.

It is an arithmetic number, because the mean of its divisors is an integer number (225546).

2⁸²⁶⁹⁹¹ is an apocalyptic number.

826991 is a deficient number, since it is larger than the sum of its proper divisors (75193).

826991 is a wasteful number, since it uses less digits than its factorization.

826991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75192.

The product of its digits is 7776, while the sum is 35.

The square root of 826991 is about 909.3904551951. The cubic root of 826991 is about 93.8642600936.

The spelling of 826991 in words is "eight hundred twenty-six thousand, nine hundred ninety-one".