1644065073 has 16 divisors (see below), whose sum is σ = 2783602560. Its totient is φ = 939465648.

The previous prime is 1644065063. The next prime is 1644065119. The reversal of 1644065073 is 3705604461.

It is a happy number.

1644065073 is a `hidden beast` number, since 1 + 644 + 0 + 6 + 5 + 0 + 7 + 3 = 666.

It is not a de Polignac number, because 1644065073 - 2¹³ = 1644056881 is a prime.

It is a super-3 number, since 3×1644065073³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1644065063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4349190 + ... + 4349567.

It is an arithmetic number, because the mean of its divisors is an integer number (173975160).

Almost surely, 2^1644065073 is an apocalyptic number.

It is an amenable number.

1644065073 is a deficient number, since it is larger than the sum of its proper divisors (1139537487).

1644065073 is an equidigital number, since it uses as much as digits as its factorization.

1644065073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8698773 (or 8698767 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The square root of 1644065073 is about 40547.0723110806. The cubic root of 1644065073 is about 1180.2472604992.

The spelling of 1644065073 in words is "one billion, six hundred forty-four million, sixty-five thousand, seventy-three".