550666681 has 2 divisors, whose sum is σ = 550666682. Its totient is φ = 550666680.

The previous prime is 550666679. The next prime is 550666687. The reversal of 550666681 is 186666055.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 533194281 + 17472400 = 23091^2 + 4180^2 .

It is a cyclic number.

It is not a de Polignac number, because 550666681 - 2¹ = 550666679 is a prime.

It is a super-2 number, since 2×550666681² = 606467587127111522, which contains 22 as substring.

Together with 550666679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (550666687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 275333340 + 275333341.

It is an arithmetic number, because the mean of its divisors is an integer number (275333341).

Almost surely, 2^550666681 is an apocalyptic number.

It is an amenable number.

550666681 is a deficient number, since it is larger than the sum of its proper divisors (1).

550666681 is an equidigital number, since it uses as much as digits as its factorization.

550666681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 259200, while the sum is 43.

The square root of 550666681 is about 23466.2881811334. The cubic root of 550666681 is about 819.6521829464.

The spelling of 550666681 in words is "five hundred fifty million, six hundred sixty-six thousand, six hundred eighty-one".