1891138 has 8 divisors (see below), whose sum is σ = 2875788. Its totient is φ = 932544.

The previous prime is 1891133. The next prime is 1891147. The reversal of 1891138 is 8311981.

It can be written as a sum of positive squares in 2 ways, for example, as 1814409 + 76729 = 1347^2 + 277^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1891133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6331 + ... + 6622.

2^1891138 is an apocalyptic number.

1891138 is a deficient number, since it is larger than the sum of its proper divisors (984650).

1891138 is a wasteful number, since it uses less digits than its factorization.

1891138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13028.

The product of its digits is 1728, while the sum is 31.

The square root of 1891138 is about 1375.1865328020. The cubic root of 1891138 is about 123.6633689502.

The spelling of 1891138 in words is "one million, eight hundred ninety-one thousand, one hundred thirty-eight".