1644222653 has 4 divisors (see below), whose sum is σ = 1661173500. Its totient is φ = 1627271808.

The previous prime is 1644222647. The next prime is 1644222661. The reversal of 1644222653 is 3562224461.

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 262018969 + 1382203684 = 16187^2 + 37178^2 .

It is a cyclic number.

It is not a de Polignac number, because 1644222653 - 2⁸ = 1644222397 is a prime.

It is a super-3 number, since 3×1644222653³ (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 (1644222623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8475278 + ... + 8475471.

It is an arithmetic number, because the mean of its divisors is an integer number (415293375).

Almost surely, 2^1644222653 is an apocalyptic number.

It is an amenable number.

1644222653 is a deficient number, since it is larger than the sum of its proper divisors (16950847).

1644222653 is an equidigital number, since it uses as much as digits as its factorization.

1644222653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16950846.

The product of its digits is 69120, while the sum is 35.

The square root of 1644222653 is about 40549.0154381090. The cubic root of 1644222653 is about 1180.2849673241.

The spelling of 1644222653 in words is "one billion, six hundred forty-four million, two hundred twenty-two thousand, six hundred fifty-three".