555000661 has 2 divisors, whose sum is σ = 555000662. Its totient is φ = 555000660.

The previous prime is 555000647. The next prime is 555000673. The reversal of 555000661 is 166000555.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 554602500 + 398161 = 23550^2 + 631^2 .

It is a cyclic number.

It is not a de Polignac number, because 555000661 - 2¹³ = 554992469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (555000601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 277500330 + 277500331.

It is an arithmetic number, because the mean of its divisors is an integer number (277500331).

Almost surely, 2^555000661 is an apocalyptic number.

It is an amenable number.

555000661 is a deficient number, since it is larger than the sum of its proper divisors (1).

555000661 is an equidigital number, since it uses as much as digits as its factorization.

555000661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4500, while the sum is 28.

The square root of 555000661 is about 23558.4520077190. The cubic root of 555000661 is about 821.7969027384.

The spelling of 555000661 in words is "five hundred fifty-five million, six hundred sixty-one", and thus it is an aban number.