550115561 has 2 divisors, whose sum is σ = 550115562. Its totient is φ = 550115560.

The previous prime is 550115557. The next prime is 550115581. The reversal of 550115561 is 165511055.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 400200025 + 149915536 = 20005^2 + 12244^2 .

It is a cyclic number.

It is not a de Polignac number, because 550115561 - 2² = 550115557 is a prime.

It is not a weakly prime, because it can be changed into another prime (550115521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 275057780 + 275057781.

It is an arithmetic number, because the mean of its divisors is an integer number (275057781).

Almost surely, 2^550115561 is an apocalyptic number.

It is an amenable number.

550115561 is a deficient number, since it is larger than the sum of its proper divisors (1).

550115561 is an equidigital number, since it uses as much as digits as its factorization.

550115561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3750, while the sum is 29.

The square root of 550115561 is about 23454.5424385128. The cubic root of 550115561 is about 819.3786493612.

The spelling of 550115561 in words is "five hundred fifty million, one hundred fifteen thousand, five hundred sixty-one".