1644305045 has 4 divisors (see below), whose sum is σ = 1973166060. Its totient is φ = 1315444032.

The previous prime is 1644305027. The next prime is 1644305051. The reversal of 1644305045 is 5405034461.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 350176369 + 1294128676 = 18713^2 + 35974^2 .

It is a cyclic number.

It is not a de Polignac number, because 1644305045 - 2⁸ = 1644304789 is a prime.

It is a super-3 number, since 3×1644305045³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164430500 + ... + 164430509.

It is an arithmetic number, because the mean of its divisors is an integer number (493291515).

Almost surely, 2^1644305045 is an apocalyptic number.

It is an amenable number.

1644305045 is a deficient number, since it is larger than the sum of its proper divisors (328861015).

1644305045 is an equidigital number, since it uses as much as digits as its factorization.

1644305045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328861014.

The product of its (nonzero) digits is 28800, while the sum is 32.

The square root of 1644305045 is about 40550.0313809990. The cubic root of 1644305045 is about 1180.3046816887.

The spelling of 1644305045 in words is "one billion, six hundred forty-four million, three hundred five thousand, forty-five".