666181049 has 2 divisors, whose sum is σ = 666181050. Its totient is φ = 666181048.

The previous prime is 666181027. The next prime is 666181063. The reversal of 666181049 is 940181666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 665898025 + 283024 = 25805^2 + 532^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666181049 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 666180997 and 666181015.

It is not a weakly prime, because it can be changed into another prime (666189049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333090524 + 333090525.

It is an arithmetic number, because the mean of its divisors is an integer number (333090525).

Almost surely, 2^666181049 is an apocalyptic number.

It is an amenable number.

666181049 is a deficient number, since it is larger than the sum of its proper divisors (1).

666181049 is an equidigital number, since it uses as much as digits as its factorization.

666181049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 666181049 is about 25810.4833158932. The cubic root of 666181049 is about 873.3683001591.

The spelling of 666181049 in words is "six hundred sixty-six million, one hundred eighty-one thousand, forty-nine".