66423605251 has 8 divisors (see below), whose sum is σ = 69354704160. Its totient is φ = 63496099392.

The previous prime is 66423605207. The next prime is 66423605257. The reversal of 66423605251 is 15250632466.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66423605251 - 2²⁷ = 66289387523 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66423605257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 860440 + ... + 934453.

It is an arithmetic number, because the mean of its divisors is an integer number (8669338020).

Almost surely, 2^66423605251 is an apocalyptic number.

66423605251 is a deficient number, since it is larger than the sum of its proper divisors (2931098909).

66423605251 is a wasteful number, since it uses less digits than its factorization.

66423605251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1796525.

The product of its (nonzero) digits is 259200, while the sum is 40.

The spelling of 66423605251 in words is "sixty-six billion, four hundred twenty-three million, six hundred five thousand, two hundred fifty-one".