666163517 has 2 divisors, whose sum is σ = 666163518. Its totient is φ = 666163516.

The previous prime is 666163499. The next prime is 666163567. The reversal of 666163517 is 715361666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 537590596 + 128572921 = 23186^2 + 11339^2 .

It is a cyclic number.

It is not a de Polignac number, because 666163517 - 2¹⁶ = 666097981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666163567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333081758 + 333081759.

It is an arithmetic number, because the mean of its divisors is an integer number (333081759).

Almost surely, 2^666163517 is an apocalyptic number.

It is an amenable number.

666163517 is a deficient number, since it is larger than the sum of its proper divisors (1).

666163517 is an equidigital number, since it uses as much as digits as its factorization.

666163517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 41.

The square root of 666163517 is about 25810.1436842184. The cubic root of 666163517 is about 873.3606385645.

The spelling of 666163517 in words is "six hundred sixty-six million, one hundred sixty-three thousand, five hundred seventeen".