1644343028 has 6 divisors (see below), whose sum is σ = 2877600306. Its totient is φ = 822171512.

The previous prime is 1644343027. The next prime is 1644343079. The reversal of 1644343028 is 8203434461.

It can be written as a sum of positive squares in only one way, i.e., 1444912144 + 199430884 = 38012^2 + 14122^2 .

It is a super-3 number, since 3×1644343028³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644343021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205542875 + ... + 205542882.

It is an arithmetic number, because the mean of its divisors is an integer number (479600051).

Almost surely, 2^1644343028 is an apocalyptic number.

It is an amenable number.

1644343028 is a deficient number, since it is larger than the sum of its proper divisors (1233257278).

1644343028 is a wasteful number, since it uses less digits than its factorization.

1644343028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411085761 (or 411085759 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 35.

The square root of 1644343028 is about 40550.4997256507. The cubic root of 1644343028 is about 1180.3137698580.

Adding to 1644343028 its reverse (8203434461), we get a palindrome (9847777489).

The spelling of 1644343028 in words is "one billion, six hundred forty-four million, three hundred forty-three thousand, twenty-eight".