550661 has 2 divisors, whose sum is σ = 550662. Its totient is φ = 550660.

The previous prime is 550657. The next prime is 550663. The reversal of 550661 is 166055.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 448900 + 101761 = 670^2 + 319^2 .

It is a cyclic number.

It is not a de Polignac number, because 550661 - 2² = 550657 is a prime.

It is a Sophie Germain prime.

Together with 550663, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (550663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 275330 + 275331.

It is an arithmetic number, because the mean of its divisors is an integer number (275331).

2⁵⁵⁰⁶⁶¹ is an apocalyptic number.

It is an amenable number.

550661 is a deficient number, since it is larger than the sum of its proper divisors (1).

550661 is an equidigital number, since it uses as much as digits as its factorization.

550661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 550661 is about 742.0653610027. The cubic root of 550661 is about 81.9649364266.

The spelling of 550661 in words is "five hundred fifty thousand, six hundred sixty-one".