1664813733 has 16 divisors (see below), whose sum is σ = 2480611392. Its totient is φ = 984368000.

The previous prime is 1664813729. The next prime is 1664813747. The reversal of 1664813733 is 3373184661.

It is a happy number.

It is not a de Polignac number, because 1664813733 - 2² = 1664813729 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664813833) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 613878 + ... + 616583.

It is an arithmetic number, because the mean of its divisors is an integer number (155038212).

Almost surely, 2^1664813733 is an apocalyptic number.

It is an amenable number.

1664813733 is a deficient number, since it is larger than the sum of its proper divisors (815797659).

1664813733 is a wasteful number, since it uses less digits than its factorization.

1664813733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1230516.

The product of its digits is 217728, while the sum is 42.

The square root of 1664813733 is about 40802.1290253340. The cubic root of 1664813733 is about 1185.1915594111.

It can be divided in two parts, 16648 and 13733, that added together give a triangular number (30381 = T₂₄₆).

The spelling of 1664813733 in words is "one billion, six hundred sixty-four million, eight hundred thirteen thousand, seven hundred thirty-three".