891679 has 2 divisors, whose sum is σ = 891680. Its totient is φ = 891678.

The previous prime is 891677. The next prime is 891707. The reversal of 891679 is 976198.

891679 = 383² + 384² + ... + 388².

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 891679 - 2¹ = 891677 is a prime.

Together with 891677, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (891677) 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 as a sum of consecutive naturals, namely, 445839 + 445840.

It is an arithmetic number, because the mean of its divisors is an integer number (445840).

2⁸⁹¹⁶⁷⁹ is an apocalyptic number.

891679 is a deficient number, since it is larger than the sum of its proper divisors (1).

891679 is an equidigital number, since it uses as much as digits as its factorization.

891679 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27216, while the sum is 40.

The square root of 891679 is about 944.2875621335. The cubic root of 891679 is about 96.2504671929.

The spelling of 891679 in words is "eight hundred ninety-one thousand, six hundred seventy-nine".