666101959 has 2 divisors, whose sum is σ = 666101960. Its totient is φ = 666101958.

The previous prime is 666101951. The next prime is 666101971. The reversal of 666101959 is 959101666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 666101959 - 2³ = 666101951 is a prime.

It is equal to p_34586665 and since 666101959 and 34586665 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 (666101951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333050979 + 333050980.

It is an arithmetic number, because the mean of its divisors is an integer number (333050980).

Almost surely, 2^666101959 is an apocalyptic number.

666101959 is a deficient number, since it is larger than the sum of its proper divisors (1).

666101959 is an equidigital number, since it uses as much as digits as its factorization.

666101959 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 87480, while the sum is 43.

The square root of 666101959 is about 25808.9511410286. The cubic root of 666101959 is about 873.3337362655. Note that the first 3 decimals are identical.

The spelling of 666101959 in words is "six hundred sixty-six million, one hundred one thousand, nine hundred fifty-nine".