646545545646 has 384 divisors, whose sum is σ = 1826698148352. Its totient is φ = 149869440000.

The previous prime is 646545545641. The next prime is 646545545647.

646545545646 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×646545545646² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 646545545646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646545545641) 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 191 ways as a sum of consecutive naturals, for example, 182586636 + ... + 182590176.

It is an arithmetic number, because the mean of its divisors is an integer number (4757026428).

Almost surely, 2^646545545646 is an apocalyptic number.

646545545646 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 646545545646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (913349074176).

646545545646 is an abundant number, since it is smaller than the sum of its proper divisors (1180152602706).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646545545646 is a wasteful number, since it uses less digits than its factorization.

646545545646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3728 (or 3721 counting only the distinct ones).

The product of its digits is 207360000, while the sum is 60.

The spelling of 646545545646 in words is "six hundred forty-six billion, five hundred forty-five million, five hundred forty-five thousand, six hundred forty-six".