66400259 has 2 divisors, whose sum is σ = 66400260. Its totient is φ = 66400258.

The previous prime is 66400253. The next prime is 66400261. The reversal of 66400259 is 95200466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66400259 - 2¹² = 66396163 is a prime.

Together with 66400261, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_3918515 and since 66400259 and 3918515 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (66400253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33200129 + 33200130.

It is an arithmetic number, because the mean of its divisors is an integer number (33200130).

Almost surely, 2^66400259 is an apocalyptic number.

66400259 is a deficient number, since it is larger than the sum of its proper divisors (1).

66400259 is an equidigital number, since it uses as much as digits as its factorization.

66400259 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 66400259 is about 8148.6354072323. The cubic root of 66400259 is about 404.9392969021.

The spelling of 66400259 in words is "sixty-six million, four hundred thousand, two hundred fifty-nine".