666552109 has 2 divisors, whose sum is σ = 666552110. Its totient is φ = 666552108.

The previous prime is 666552101. The next prime is 666552137. The reversal of 666552109 is 901255666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 347822500 + 318729609 = 18650^2 + 17853^2 .

It is a cyclic number.

It is not a de Polignac number, because 666552109 - 2³ = 666552101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666552101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333276054 + 333276055.

It is an arithmetic number, because the mean of its divisors is an integer number (333276055).

Almost surely, 2^666552109 is an apocalyptic number.

It is an amenable number.

666552109 is a deficient number, since it is larger than the sum of its proper divisors (1).

666552109 is an equidigital number, since it uses as much as digits as its factorization.

666552109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 97200, while the sum is 40.

The square root of 666552109 is about 25817.6704797315. The cubic root of 666552109 is about 873.5304242001.

The spelling of 666552109 in words is "six hundred sixty-six million, five hundred fifty-two thousand, one hundred nine".