646422552251 has 4 divisors (see below), whose sum is σ = 738768631152. Its totient is φ = 554076473352.

The previous prime is 646422552203. The next prime is 646422552263. The reversal of 646422552251 is 152255224646.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 646422552251 - 2²⁶ = 646355443387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646422557251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46173039440 + ... + 46173039453.

It is an arithmetic number, because the mean of its divisors is an integer number (184692157788).

Almost surely, 2^646422552251 is an apocalyptic number.

646422552251 is a deficient number, since it is larger than the sum of its proper divisors (92346078901).

646422552251 is an equidigital number, since it uses as much as digits as its factorization.

646422552251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92346078900.

The product of its digits is 1152000, while the sum is 44.

Adding to 646422552251 its reverse (152255224646), we get a palindrome (798677776897).

The spelling of 646422552251 in words is "six hundred forty-six billion, four hundred twenty-two million, five hundred fifty-two thousand, two hundred fifty-one".