666504101 has 2 divisors, whose sum is σ = 666504102. Its totient is φ = 666504100.

The previous prime is 666504049. The next prime is 666504103. The reversal of 666504101 is 101405666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 389115076 + 277389025 = 19726^2 + 16655^2 .

It is a cyclic number.

It is not a de Polignac number, because 666504101 - 2⁶ = 666504037 is a prime.

Together with 666504103, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666504103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333252050 + 333252051.

It is an arithmetic number, because the mean of its divisors is an integer number (333252051).

Almost surely, 2^666504101 is an apocalyptic number.

It is an amenable number.

666504101 is a deficient number, since it is larger than the sum of its proper divisors (1).

666504101 is an equidigital number, since it uses as much as digits as its factorization.

666504101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 666504101 is about 25816.7407121813. The cubic root of 666504101 is about 873.5094518685.

Adding to 666504101 its reverse (101405666), we get a palindrome (767909767).

The spelling of 666504101 in words is "six hundred sixty-six million, five hundred four thousand, one hundred one".