891197 has 4 divisors (see below), whose sum is σ = 894780. Its totient is φ = 887616.

The previous prime is 891179. The next prime is 891223. The reversal of 891197 is 791198.

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

It can be written as a sum of positive squares in 2 ways, for example, as 436921 + 454276 = 661^2 + 674^2 .

It is a cyclic number.

It is not a de Polignac number, because 891197 - 2⁶ = 891133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891797) 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, 1388 + ... + 1925.

It is an arithmetic number, because the mean of its divisors is an integer number (223695).

2⁸⁹¹¹⁹⁷ is an apocalyptic number.

It is an amenable number.

891197 is a deficient number, since it is larger than the sum of its proper divisors (3583).

891197 is a wasteful number, since it uses less digits than its factorization.

891197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3582.

The product of its digits is 4536, while the sum is 35.

The square root of 891197 is about 944.0323087691. The cubic root of 891197 is about 96.2331212321.

Subtracting from 891197 its reverse (791198), we obtain a palindrome (99999).

The spelling of 891197 in words is "eight hundred ninety-one thousand, one hundred ninety-seven".