1644233202221 has 16 divisors (see below), whose sum is σ = 1708245000000. Its totient is φ = 1581411541248.

The previous prime is 1644233202149. The next prime is 1644233202233. The reversal of 1644233202221 is 1222023324461.

It is a cyclic number.

It is not a de Polignac number, because 1644233202221 - 2²⁶ = 1644166093357 is a prime.

It is a super-3 number, since 3×1644233202221³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644233202421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7407155 + ... + 7625903.

It is an arithmetic number, because the mean of its divisors is an integer number (106765312500).

Almost surely, 2^{1644233202221} is an apocalyptic number.

It is an amenable number.

1644233202221 is a deficient number, since it is larger than the sum of its proper divisors (64011797779).

1644233202221 is a wasteful number, since it uses less digits than its factorization.

1644233202221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221468.

The product of its (nonzero) digits is 27648, while the sum is 32.

Adding to 1644233202221 its reverse (1222023324461), we get a palindrome (2866256526682).

The spelling of 1644233202221 in words is "one trillion, six hundred forty-four billion, two hundred thirty-three million, two hundred two thousand, two hundred twenty-one".