555420661 has 2 divisors, whose sum is σ = 555420662. Its totient is φ = 555420660.

The previous prime is 555420659. The next prime is 555420683. The reversal of 555420661 is 166024555.

555420661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 525280561 + 30140100 = 22919^2 + 5490^2 .

It is a cyclic number.

It is not a de Polignac number, because 555420661 - 2¹ = 555420659 is a prime.

It is a super-2 number, since 2×555420661² = 616984221331353842, which contains 22 as substring.

Together with 555420659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (555420641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 277710330 + 277710331.

It is an arithmetic number, because the mean of its divisors is an integer number (277710331).

Almost surely, 2^555420661 is an apocalyptic number.

It is an amenable number.

555420661 is a deficient number, since it is larger than the sum of its proper divisors (1).

555420661 is an equidigital number, since it uses as much as digits as its factorization.

555420661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36000, while the sum is 34.

The square root of 555420661 is about 23567.3643201780. The cubic root of 555420661 is about 822.0041503412.

The spelling of 555420661 in words is "five hundred fifty-five million, four hundred twenty thousand, six hundred sixty-one".