1891231 has 4 divisors (see below), whose sum is σ = 1897000. Its totient is φ = 1885464.

The previous prime is 1891223. The next prime is 1891243. The reversal of 1891231 is 1321981.

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 1891231 - 2³ = 1891223 is a prime.

It is a super-2 number, since 2×1891231² = 7153509390722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1891196 and 1891205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1891291) 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, 2361 + ... + 3058.

It is an arithmetic number, because the mean of its divisors is an integer number (474250).

2^1891231 is an apocalyptic number.

1891231 is a deficient number, since it is larger than the sum of its proper divisors (5769).

1891231 is an equidigital number, since it uses as much as digits as its factorization.

1891231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5768.

The product of its digits is 432, while the sum is 25.

The square root of 1891231 is about 1375.2203459810. The cubic root of 1891231 is about 123.6653960374.

The spelling of 1891231 in words is "one million, eight hundred ninety-one thousand, two hundred thirty-one".