1644214321 has 4 divisors (see below), whose sum is σ = 1644337444. Its totient is φ = 1644091200.

The previous prime is 1644214303. The next prime is 1644214337. The reversal of 1644214321 is 1234124461.

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 858197025 + 786017296 = 29295^2 + 28036^2 .

It is a cyclic number.

It is not a de Polignac number, because 1644214321 - 2⁵ = 1644214289 is a prime.

It is a super-3 number, since 3×1644214321³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1644214321.

It is not an unprimeable number, because it can be changed into a prime (1644254321) 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, 38700 + ... + 69181.

It is an arithmetic number, because the mean of its divisors is an integer number (411084361).

Almost surely, 2^1644214321 is an apocalyptic number.

It is an amenable number.

1644214321 is a deficient number, since it is larger than the sum of its proper divisors (123123).

1644214321 is a wasteful number, since it uses less digits than its factorization.

1644214321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123122.

The product of its digits is 4608, while the sum is 28.

The square root of 1644214321 is about 40548.9126981230. The cubic root of 1644214321 is about 1180.2829736462.

Adding to 1644214321 its reverse (1234124461), we get a palindrome (2878338782).

The spelling of 1644214321 in words is "one billion, six hundred forty-four million, two hundred fourteen thousand, three hundred twenty-one".