872191 has 4 divisors (see below), whose sum is σ = 874152. Its totient is φ = 870232.

The previous prime is 872189. The next prime is 872203. The reversal of 872191 is 191278.

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

It is a cyclic number.

It is not a de Polignac number, because 872191 - 2¹ = 872189 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 (872141) 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, 45 + ... + 1321.

It is an arithmetic number, because the mean of its divisors is an integer number (218538).

2⁸⁷²¹⁹¹ is an apocalyptic number.

872191 is a deficient number, since it is larger than the sum of its proper divisors (1961).

872191 is a wasteful number, since it uses less digits than its factorization.

872191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1960.

The product of its digits is 1008, while the sum is 28.

The square root of 872191 is about 933.9116660584. The cubic root of 872191 is about 95.5440984901.

It can be divided in two parts, 87 and 2191, that added together give a triangular number (2278 = T₆₇).

The spelling of 872191 in words is "eight hundred seventy-two thousand, one hundred ninety-one".