1691138 has 8 divisors (see below), whose sum is σ = 2542332. Its totient is φ = 843696.

The previous prime is 1691119. The next prime is 1691141. The reversal of 1691138 is 8311961.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1605289 + 85849 = 1267^2 + 293^2 .

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1691138.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 956 + ... + 2072.

2^1691138 is an apocalyptic number.

1691138 is a deficient number, since it is larger than the sum of its proper divisors (851194).

1691138 is a wasteful number, since it uses less digits than its factorization.

1691138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1876.

The product of its digits is 1296, while the sum is 29.

The square root of 1691138 is about 1300.4376186500. The cubic root of 1691138 is about 119.1405725273.

The spelling of 1691138 in words is "one million, six hundred ninety-one thousand, one hundred thirty-eight".