1644963379 has 2 divisors, whose sum is σ = 1644963380. Its totient is φ = 1644963378.

The previous prime is 1644963377. The next prime is 1644963443. The reversal of 1644963379 is 9733694461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1644963379 - 2¹ = 1644963377 is a prime.

Together with 1644963377, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1644963373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822481689 + 822481690.

It is an arithmetic number, because the mean of its divisors is an integer number (822481690).

Almost surely, 2^1644963379 is an apocalyptic number.

1644963379 is a deficient number, since it is larger than the sum of its proper divisors (1).

1644963379 is an equidigital number, since it uses as much as digits as its factorization.

1644963379 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2939328, while the sum is 52.

The square root of 1644963379 is about 40558.1481209387. The cubic root of 1644963379 is about 1180.4621810584.

The spelling of 1644963379 in words is "one billion, six hundred forty-four million, nine hundred sixty-three thousand, three hundred seventy-nine".