255557661 has 4 divisors (see below), whose sum is σ = 340743552. Its totient is φ = 170371772.

The previous prime is 255557647. The next prime is 255557663. The reversal of 255557661 is 166755552.

It is a happy number.

255557661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 255557661 - 2⁵ = 255557629 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255557663) 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, 42592941 + ... + 42592946.

It is an arithmetic number, because the mean of its divisors is an integer number (85185888).

Almost surely, 2^255557661 is an apocalyptic number.

It is an amenable number.

255557661 is a deficient number, since it is larger than the sum of its proper divisors (85185891).

255557661 is an equidigital number, since it uses as much as digits as its factorization.

255557661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85185890.

The product of its digits is 315000, while the sum is 42.

The square root of 255557661 is about 15986.1709299006. The cubic root of 255557661 is about 634.5944967218.

The spelling of 255557661 in words is "two hundred fifty-five million, five hundred fifty-seven thousand, six hundred sixty-one".