646543345647 has 16 divisors (see below), whose sum is σ = 866699981280. Its totient is φ = 428713587072.

The previous prime is 646543345639. The next prime is 646543345663. The reversal of 646543345647 is 746543345646.

It is not a de Polignac number, because 646543345647 - 2³ = 646543345639 is a prime.

It is a super-2 number, since 2×646543345647² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646543340647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 275128 + ... + 1169949.

It is an arithmetic number, because the mean of its divisors is an integer number (54168748830).

Almost surely, 2^646543345647 is an apocalyptic number.

646543345647 is a deficient number, since it is larger than the sum of its proper divisors (220156635633).

646543345647 is a wasteful number, since it uses less digits than its factorization.

646543345647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1445882.

The product of its digits is 87091200, while the sum is 57.

Subtracting 646543345647 from its reverse (746543345646), we obtain a palindrome (99999999999).

The spelling of 646543345647 in words is "six hundred forty-six billion, five hundred forty-three million, three hundred forty-five thousand, six hundred forty-seven".