535665661 has 4 divisors (see below), whose sum is σ = 544744800. Its totient is φ = 526586524.

The previous prime is 535665587. The next prime is 535665667. The reversal of 535665661 is 166566535.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 166566535 = 5 ⋅33313307.

It is a cyclic number.

It is not a de Polignac number, because 535665661 - 2²³ = 527277053 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (535665667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4539481 + ... + 4539598.

It is an arithmetic number, because the mean of its divisors is an integer number (136186200).

Almost surely, 2^535665661 is an apocalyptic number.

It is an amenable number.

535665661 is a deficient number, since it is larger than the sum of its proper divisors (9079139).

535665661 is an equidigital number, since it uses as much as digits as its factorization.

535665661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9079138.

The product of its digits is 486000, while the sum is 43.

The square root of 535665661 is about 23144.4520565945. The cubic root of 535665661 is about 812.1406877044.

It can be divided in two parts, 5356 and 65661, that added together give a palindrome (71017).

The spelling of 535665661 in words is "five hundred thirty-five million, six hundred sixty-five thousand, six hundred sixty-one".