891439 has 2 divisors, whose sum is σ = 891440. Its totient is φ = 891438.

The previous prime is 891427. The next prime is 891481. The reversal of 891439 is 934198.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 891439 - 2⁷ = 891311 is a prime.

891439 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (891409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445719 + 445720.

It is an arithmetic number, because the mean of its divisors is an integer number (445720).

2⁸⁹¹⁴³⁹ is an apocalyptic number.

891439 is a deficient number, since it is larger than the sum of its proper divisors (1).

891439 is an equidigital number, since it uses as much as digits as its factorization.

891439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 34.

The square root of 891439 is about 944.1604736484. The cubic root of 891439 is about 96.2418309815.

The spelling of 891439 in words is "eight hundred ninety-one thousand, four hundred thirty-nine".