1691131 has 4 divisors (see below), whose sum is σ = 1821232. Its totient is φ = 1561032.

The previous prime is 1691119. The next prime is 1691141. The reversal of 1691131 is 1311961.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1311961 = 7 ⋅187423.

It is a cyclic number.

It is not a de Polignac number, because 1691131 - 2⁵ = 1691099 is a prime.

It is a super-2 number, since 2×1691131² = 5719848118322, which contains 22 as substring.

It is a Duffinian number.

1691131 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1691101) 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, 65031 + ... + 65056.

It is an arithmetic number, because the mean of its divisors is an integer number (455308).

2^1691131 is an apocalyptic number.

1691131 is a deficient number, since it is larger than the sum of its proper divisors (130101).

1691131 is a wasteful number, since it uses less digits than its factorization.

1691131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130100.

The product of its digits is 162, while the sum is 22.

The square root of 1691131 is about 1300.4349272455. The cubic root of 1691131 is about 119.1404081438.

The spelling of 1691131 in words is "one million, six hundred ninety-one thousand, one hundred thirty-one".