1644014989 has 2 divisors, whose sum is σ = 1644014990. Its totient is φ = 1644014988.

The previous prime is 1644014987. The next prime is 1644014993. The reversal of 1644014989 is 9894104461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1262594089 + 381420900 = 35533^2 + 19530^2 .

It is a cyclic number.

It is not a de Polignac number, because 1644014989 - 2¹ = 1644014987 is a prime.

It is a super-3 number, since 3×1644014989³ (a number of 29 digits) contains 333 as substring.

Together with 1644014987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1644014987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822007494 + 822007495.

It is an arithmetic number, because the mean of its divisors is an integer number (822007495).

Almost surely, 2^1644014989 is an apocalyptic number.

It is an amenable number.

1644014989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1644014989 is an equidigital number, since it uses as much as digits as its factorization.

1644014989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 248832, while the sum is 46.

The square root of 1644014989 is about 40546.4547032167. The cubic root of 1644014989 is about 1180.2352755510.

The spelling of 1644014989 in words is "one billion, six hundred forty-four million, fourteen thousand, nine hundred eighty-nine".