1644142441 has 2 divisors, whose sum is σ = 1644142442. Its totient is φ = 1644142440.

The previous prime is 1644142421. The next prime is 1644142477. The reversal of 1644142441 is 1442414461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1581732441 + 62410000 = 39771^2 + 7900^2 .

It is a cyclic number.

It is not a de Polignac number, because 1644142441 - 2¹³ = 1644134249 is a prime.

It is a super-3 number, since 3×1644142441³ (a number of 29 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (1644142411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822071220 + 822071221.

It is an arithmetic number, because the mean of its divisors is an integer number (822071221).

Almost surely, 2^1644142441 is an apocalyptic number.

It is an amenable number.

1644142441 is a deficient number, since it is larger than the sum of its proper divisors (1).

1644142441 is an equidigital number, since it uses as much as digits as its factorization.

1644142441 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12288, while the sum is 31.

The square root of 1644142441 is about 40548.0263514761. The cubic root of 1644142441 is about 1180.2657739468.

The spelling of 1644142441 in words is "one billion, six hundred forty-four million, one hundred forty-two thousand, four hundred forty-one".