666355673 has 2 divisors, whose sum is σ = 666355674. Its totient is φ = 666355672.

The previous prime is 666355637. The next prime is 666355693. The reversal of 666355673 is 376553666.

Together with previous prime (666355637) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 549996304 + 116359369 = 23452^2 + 10787^2 .

It is a cyclic number.

It is not a de Polignac number, because 666355673 - 2²² = 662161369 is a prime.

It is not a weakly prime, because it can be changed into another prime (666355693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333177836 + 333177837.

It is an arithmetic number, because the mean of its divisors is an integer number (333177837).

Almost surely, 2^666355673 is an apocalyptic number.

It is an amenable number.

666355673 is a deficient number, since it is larger than the sum of its proper divisors (1).

666355673 is an equidigital number, since it uses as much as digits as its factorization.

666355673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2041200, while the sum is 47.

The square root of 666355673 is about 25813.8659057492. The cubic root of 666355673 is about 873.4446046124. Note that the first 3 decimals are identical.

The spelling of 666355673 in words is "six hundred sixty-six million, three hundred fifty-five thousand, six hundred seventy-three".