1645885380864 has 144 divisors (see below), whose sum is σ = 4500034818048. Its totient is φ = 533659631616.

The previous prime is 1645885380847. The next prime is 1645885381001. The reversal of 1645885380864 is 4680835885461.

It is a junction number, because it is equal to n+sod(n) for n = 1645885380795 and 1645885380804.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 194844289 + ... + 194852735.

It is an arithmetic number, because the mean of its divisors is an integer number (31250241792).

Almost surely, 2^{1645885380864} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1645885380864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2250017409024).

1645885380864 is an abundant number, since it is smaller than the sum of its proper divisors (2854149437184).

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

1645885380864 is an equidigital number, since it uses as much as digits as its factorization.

1645885380864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15360 (or 15346 counting only the distinct ones).

The product of its (nonzero) digits is 176947200, while the sum is 66.

The spelling of 1645885380864 in words is "one trillion, six hundred forty-five billion, eight hundred eighty-five million, three hundred eighty thousand, eight hundred sixty-four".