891971 has 4 divisors (see below), whose sum is σ = 905352. Its totient is φ = 878592.

The previous prime is 891967. The next prime is 891983. The reversal of 891971 is 179198.

891971 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, and also an emirpimes, since its reverse is a distinct semiprime: 179198 = 2 ⋅89599.

It is a cyclic number.

It is not a de Polignac number, because 891971 - 2² = 891967 is a prime.

It is a super-2 number, since 2×891971² = 1591224529682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (891991) 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, 6590 + ... + 6723.

It is an arithmetic number, because the mean of its divisors is an integer number (226338).

2⁸⁹¹⁹⁷¹ is an apocalyptic number.

891971 is a deficient number, since it is larger than the sum of its proper divisors (13381).

891971 is a wasteful number, since it uses less digits than its factorization.

891971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13380.

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

The square root of 891971 is about 944.4421633959. The cubic root of 891971 is about 96.2609724940.

It can be divided in two parts, 89197 and 1, that added together give a palindrome (89198).

The spelling of 891971 in words is "eight hundred ninety-one thousand, nine hundred seventy-one".