1644445452 has 48 divisors (see below), whose sum is σ = 4143847680. Its totient is φ = 504556608.

The previous prime is 1644445423. The next prime is 1644445471. The reversal of 1644445452 is 2545444461.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 1644445452.

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, 41323 + ... + 70685.

It is an arithmetic number, because the mean of its divisors is an integer number (86330160).

Almost surely, 2^1644445452 is an apocalyptic number.

1644445452 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1644445452, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2071923840).

1644445452 is an abundant number, since it is smaller than the sum of its proper divisors (2499402228).

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

1644445452 is a wasteful number, since it uses less digits than its factorization.

1644445452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29742 (or 29740 counting only the distinct ones).

The product of its digits is 307200, while the sum is 39.

The square root of 1644445452 is about 40551.7626250697. The cubic root of 1644445452 is about 1180.3382760884.

Subtracting 1644445452 from its reverse (2545444461), we obtain a palindrome (900999009).

The spelling of 1644445452 in words is "one billion, six hundred forty-four million, four hundred forty-five thousand, four hundred fifty-two".