1661135 has 16 divisors (see below), whose sum is σ = 2353152. Its totient is φ = 1101600.

The previous prime is 1661123. The next prime is 1661137. The reversal of 1661135 is 5311661.

It is a happy number.

It is not a de Polignac number, because 1661135 - 2¹⁰ = 1660111 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1661135.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661137) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 320 + ... + 1850.

It is an arithmetic number, because the mean of its divisors is an integer number (147072).

2^1661135 is an apocalyptic number.

1661135 is a deficient number, since it is larger than the sum of its proper divisors (692017).

1661135 is a wasteful number, since it uses less digits than its factorization.

1661135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1574.

The product of its digits is 540, while the sum is 23.

The square root of 1661135 is about 1288.8502628312. The cubic root of 1661135 is about 118.4317944425.

Adding to 1661135 its reverse (5311661), we get a palindrome (6972796).

The spelling of 1661135 in words is "one million, six hundred sixty-one thousand, one hundred thirty-five".