1644290113 has 4 divisors (see below), whose sum is σ = 1647888580. Its totient is φ = 1640691648.

The previous prime is 1644290059. The next prime is 1644290147. The reversal of 1644290113 is 3110924461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3110924461 = 1019 ⋅3052919.

It can be written as a sum of positive squares in 2 ways, for example, as 756965169 + 887324944 = 27513^2 + 29788^2 .

It is a cyclic number.

It is not a de Polignac number, because 1644290113 - 2⁹ = 1644289601 is a prime.

It is a super-3 number, since 3×1644290113³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1644290513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1798548 + ... + 1799461.

It is an arithmetic number, because the mean of its divisors is an integer number (411972145).

Almost surely, 2^1644290113 is an apocalyptic number.

It is an amenable number.

1644290113 is a deficient number, since it is larger than the sum of its proper divisors (3598467).

1644290113 is an equidigital number, since it uses as much as digits as its factorization.

1644290113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3598466.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 1644290113 is about 40549.8472623511. The cubic root of 1644290113 is about 1180.3011088799.

The spelling of 1644290113 in words is "one billion, six hundred forty-four million, two hundred ninety thousand, one hundred thirteen".