666041951 has 2 divisors, whose sum is σ = 666041952. Its totient is φ = 666041950.

The previous prime is 666041939. The next prime is 666041953. The reversal of 666041951 is 159140666.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666041951 is a prime.

It is a super-2 number, since 2×666041951² = 887223760983772802, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 666041953, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_34583726 and since 666041951 and 34583726 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666041953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333020975 + 333020976.

It is an arithmetic number, because the mean of its divisors is an integer number (333020976).

Almost surely, 2^666041951 is an apocalyptic number.

666041951 is a deficient number, since it is larger than the sum of its proper divisors (1).

666041951 is an equidigital number, since it uses as much as digits as its factorization.

666041951 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 666041951 is about 25807.7885724446. The cubic root of 666041951 is about 873.3075097577.

The spelling of 666041951 in words is "six hundred sixty-six million, forty-one thousand, nine hundred fifty-one".