1644342305 has 4 divisors (see below), whose sum is σ = 1973210772. Its totient is φ = 1315473840.

The previous prime is 1644342263. The next prime is 1644342361. The reversal of 1644342305 is 5032434461.

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 1271350336 + 372991969 = 35656^2 + 19313^2 .

It is not a de Polignac number, because 1644342305 - 2⁶ = 1644342241 is a prime.

It is a super-3 number, since 3×1644342305³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164434226 + ... + 164434235.

It is an arithmetic number, because the mean of its divisors is an integer number (493302693).

Almost surely, 2^1644342305 is an apocalyptic number.

It is an amenable number.

1644342305 is a deficient number, since it is larger than the sum of its proper divisors (328868467).

1644342305 is an equidigital number, since it uses as much as digits as its factorization.

1644342305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328868466.

The product of its (nonzero) digits is 34560, while the sum is 32.

The square root of 1644342305 is about 40550.4908108398. The cubic root of 1644342305 is about 1180.3135968675.

Adding to 1644342305 its reverse (5032434461), we get a palindrome (6676776766).

The spelling of 1644342305 in words is "one billion, six hundred forty-four million, three hundred forty-two thousand, three hundred five".