645663366546 has 128 divisors (see below), whose sum is σ = 1460433680640. Its totient is φ = 188581478400.

The previous prime is 645663366529. The next prime is 645663366577.

645663366546 is nontrivially palindromic in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 645663366546.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 115936050 + ... + 115941618.

It is an arithmetic number, because the mean of its divisors is an integer number (11409638130).

Almost surely, 2^645663366546 is an apocalyptic number.

645663366546 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 645663366546, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (730216840320).

645663366546 is an abundant number, since it is smaller than the sum of its proper divisors (814770314094).

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

645663366546 is a wasteful number, since it uses less digits than its factorization.

645663366546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6060.

The product of its digits is 167961600, while the sum is 60.

The spelling of 645663366546 in words is "six hundred forty-five billion, six hundred sixty-three million, three hundred sixty-six thousand, five hundred forty-six".