1644138983 has 2 divisors, whose sum is σ = 1644138984. Its totient is φ = 1644138982.

The previous prime is 1644138961. The next prime is 1644139031. The reversal of 1644138983 is 3898314461.

It is a weak prime.

It is an emirp because it is prime and its reverse (3898314461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1644138983 - 2³⁰ = 570397159 is a prime.

It is a super-3 number, since 3×1644138983³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1644138943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822069491 + 822069492.

It is an arithmetic number, because the mean of its divisors is an integer number (822069492).

Almost surely, 2^1644138983 is an apocalyptic number.

1644138983 is a deficient number, since it is larger than the sum of its proper divisors (1).

1644138983 is an equidigital number, since it uses as much as digits as its factorization.

1644138983 is an evil number, because the sum of its binary digits is even.

The product of its digits is 497664, while the sum is 47.

The square root of 1644138983 is about 40547.9837106606. The cubic root of 1644138983 is about 1180.2649464917.

The spelling of 1644138983 in words is "one billion, six hundred forty-four million, one hundred thirty-eight thousand, nine hundred eighty-three".