645443707344546 has 128 divisors (see below), whose sum is σ = 1441098027343872. Its totient is φ = 191042512416000.

The previous prime is 645443707344509. The next prime is 645443707344547.

645443707344546 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×645443707344546² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is not an unprimeable number, because it can be changed into a prime (645443707344547) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4660409676 + ... + 4660548168.

It is an arithmetic number, because the mean of its divisors is an integer number (11258578338624).

Almost surely, 2^{645443707344546} is an apocalyptic number.

645443707344546 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 645443707344546, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (720549013671936).

645443707344546 is an abundant number, since it is smaller than the sum of its proper divisors (795654319999326).

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

645443707344546 is a wasteful number, since it uses less digits than its factorization.

645443707344546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141568.

The product of its (nonzero) digits is 1625702400, while the sum is 66.

The spelling of 645443707344546 in words is "six hundred forty-five trillion, four hundred forty-three billion, seven hundred seven million, three hundred forty-four thousand, five hundred forty-six".