891598 has 4 divisors (see below), whose sum is σ = 1337400. Its totient is φ = 445798.

The previous prime is 891593. The next prime is 891601. The reversal of 891598 is 895198.

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

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 891598.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891593) by changing a digit.

891598 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 222898 + ... + 222901.

It is an arithmetic number, because the mean of its divisors is an integer number (334350).

2⁸⁹¹⁵⁹⁸ is an apocalyptic number.

891598 is a deficient number, since it is larger than the sum of its proper divisors (445802).

891598 is a wasteful number, since it uses less digits than its factorization.

891598 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445801.

The product of its digits is 25920, while the sum is 40.

The square root of 891598 is about 944.2446716821. The cubic root of 891598 is about 96.2475526448.

Subtracting 891598 from its reverse (895198), we obtain a square (3600 = 60²).

The spelling of 891598 in words is "eight hundred ninety-one thousand, five hundred ninety-eight".