1665333520 has 20 divisors (see below), whose sum is σ = 3871900620. Its totient is φ = 666133376.

The previous prime is 1665333433. The next prime is 1665333521. The reversal of 1665333520 is 253335661.

It can be written as a sum of positive squares in 2 ways, for example, as 1252593664 + 412739856 = 35392^2 + 20316^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (1665333521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10408255 + ... + 10408414.

It is an arithmetic number, because the mean of its divisors is an integer number (193595031).

Almost surely, 2^1665333520 is an apocalyptic number.

1665333520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1665333520 is an abundant number, since it is smaller than the sum of its proper divisors (2206567100).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1665333520 is a wasteful number, since it uses less digits than its factorization.

1665333520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20816682 (or 20816676 counting only the distinct ones).

The product of its (nonzero) digits is 48600, while the sum is 34.

The square root of 1665333520 is about 40808.4981345798. The cubic root of 1665333520 is about 1185.3148931411.

The spelling of 1665333520 in words is "one billion, six hundred sixty-five million, three hundred thirty-three thousand, five hundred twenty".