645546645546 has 64 divisors (see below), whose sum is σ = 1422699714432. Its totient is φ = 193644000000.

The previous prime is 645546645467. The next prime is 645546645577.

645546645546 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 645546645546.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 65195196 + ... + 65205096.

It is an arithmetic number, because the mean of its divisors is an integer number (22229683038).

Almost surely, 2^645546645546 is an apocalyptic number.

645546645546 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 645546645546, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (711349857216).

645546645546 is an abundant number, since it is smaller than the sum of its proper divisors (777153068886).

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

645546645546 is a wasteful number, since it uses less digits than its factorization.

645546645546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19799.

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

The spelling of 645546645546 in words is "six hundred forty-five billion, five hundred forty-six million, six hundred forty-five thousand, five hundred forty-six".