1644222647 has 2 divisors, whose sum is σ = 1644222648. Its totient is φ = 1644222646.

The previous prime is 1644222623. The next prime is 1644222661. The reversal of 1644222647 is 7462224461.

It is a strong prime.

It is an emirp because it is prime and its reverse (7462224461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1644222647 - 2⁶ = 1644222583 is a prime.

It is a super-3 number, since 3×1644222647³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 1644222647.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1644222607) 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 as a sum of consecutive naturals, namely, 822111323 + 822111324.

It is an arithmetic number, because the mean of its divisors is an integer number (822111324).

Almost surely, 2^1644222647 is an apocalyptic number.

1644222647 is a deficient number, since it is larger than the sum of its proper divisors (1).

1644222647 is an equidigital number, since it uses as much as digits as its factorization.

1644222647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129024, while the sum is 38.

The square root of 1644222647 is about 40549.0153641244. The cubic root of 1644222647 is about 1180.2849658884.

The spelling of 1644222647 in words is "one billion, six hundred forty-four million, two hundred twenty-two thousand, six hundred forty-seven".