666552101 has 2 divisors, whose sum is σ = 666552102. Its totient is φ = 666552100.

The previous prime is 666552097. The next prime is 666552109. The reversal of 666552101 is 101255666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 369024100 + 297528001 = 19210^2 + 17249^2 .

It is a cyclic number.

It is not a de Polignac number, because 666552101 - 2² = 666552097 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666552109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333276050 + 333276051.

It is an arithmetic number, because the mean of its divisors is an integer number (333276051).

Almost surely, 2^666552101 is an apocalyptic number.

It is an amenable number.

666552101 is a deficient number, since it is larger than the sum of its proper divisors (1).

666552101 is an equidigital number, since it uses as much as digits as its factorization.

666552101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 666552101 is about 25817.6703247989. The cubic root of 666552101 is about 873.5304207054.

The spelling of 666552101 in words is "six hundred sixty-six million, five hundred fifty-two thousand, one hundred one".