255535661 has 4 divisors (see below), whose sum is σ = 255589152. Its totient is φ = 255482172.

The previous prime is 255535613. The next prime is 255535673. The reversal of 255535661 is 166535552.

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.

It is a cyclic number.

It is not a de Polignac number, because 255535661 - 2⁶ = 255535597 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 (254535661) 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, 18791 + ... + 29396.

It is an arithmetic number, because the mean of its divisors is an integer number (63897288).

Almost surely, 2^255535661 is an apocalyptic number.

It is an amenable number.

255535661 is a deficient number, since it is larger than the sum of its proper divisors (53491).

255535661 is an equidigital number, since it uses as much as digits as its factorization.

255535661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53490.

The product of its digits is 135000, while the sum is 38.

The square root of 255535661 is about 15985.4828203592. The cubic root of 255535661 is about 634.5762862463.

The spelling of 255535661 in words is "two hundred fifty-five million, five hundred thirty-five thousand, six hundred sixty-one".