255660661 has 2 divisors, whose sum is σ = 255660662. Its totient is φ = 255660660.

The previous prime is 255660653. The next prime is 255660679. The reversal of 255660661 is 166066552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 159012100 + 96648561 = 12610^2 + 9831^2 .

It is a cyclic number.

It is not a de Polignac number, because 255660661 - 2³ = 255660653 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 255660661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (255660631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127830330 + 127830331.

It is an arithmetic number, because the mean of its divisors is an integer number (127830331).

Almost surely, 2^255660661 is an apocalyptic number.

It is an amenable number.

255660661 is a deficient number, since it is larger than the sum of its proper divisors (1).

255660661 is an equidigital number, since it uses as much as digits as its factorization.

255660661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64800, while the sum is 37.

The square root of 255660661 is about 15989.3921397907. The cubic root of 255660661 is about 634.6797409593.

The spelling of 255660661 in words is "two hundred fifty-five million, six hundred sixty thousand, six hundred sixty-one".