862991 has 2 divisors, whose sum is σ = 862992. Its totient is φ = 862990.

The previous prime is 862987. The next prime is 862997. The reversal of 862991 is 199268.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 862991 - 2² = 862987 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (862997) 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 as a sum of consecutive naturals, namely, 431495 + 431496.

It is an arithmetic number, because the mean of its divisors is an integer number (431496).

2⁸⁶²⁹⁹¹ is an apocalyptic number.

862991 is a deficient number, since it is larger than the sum of its proper divisors (1).

862991 is an equidigital number, since it uses as much as digits as its factorization.

862991 is an odious number, because the sum of its binary digits is odd.

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

The square root of 862991 is about 928.9730889536. The cubic root of 862991 is about 95.2069725727.

The spelling of 862991 in words is "eight hundred sixty-two thousand, nine hundred ninety-one".