891399 has 4 divisors (see below), whose sum is σ = 1188536. Its totient is φ = 594264.

The previous prime is 891391. The next prime is 891409. The reversal of 891399 is 993198.

891399 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 891399 - 2³ = 891391 is a prime.

It is a D-number.

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 891399.

It is not an unprimeable number, because it can be changed into a prime (891391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 148564 + ... + 148569.

It is an arithmetic number, because the mean of its divisors is an integer number (297134).

2⁸⁹¹³⁹⁹ is an apocalyptic number.

891399 is a deficient number, since it is larger than the sum of its proper divisors (297137).

891399 is a wasteful number, since it uses less digits than its factorization.

891399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297136.

The product of its digits is 17496, while the sum is 39.

The square root of 891399 is about 944.1392905710. The cubic root of 891399 is about 96.2403914623.

The spelling of 891399 in words is "eight hundred ninety-one thousand, three hundred ninety-nine".