1665723528 has 160 divisors (see below), whose sum is σ = 5368334400. Its totient is φ = 472687488.

The previous prime is 1665723517. The next prime is 1665723541. The reversal of 1665723528 is 8253275661.

It is an unprimeable number.

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 39 ways as a sum of consecutive naturals, for example, 710983 + ... + 713321.

It is an arithmetic number, because the mean of its divisors is an integer number (33552090).

Almost surely, 2^1665723528 is an apocalyptic number.

1665723528 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1665723528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2684167200).

1665723528 is an abundant number, since it is smaller than the sum of its proper divisors (3702610872).

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

1665723528 is a wasteful number, since it uses less digits than its factorization.

1665723528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2521 (or 2508 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The square root of 1665723528 is about 40813.2763693384. The cubic root of 1665723528 is about 1185.4074163909.

The spelling of 1665723528 in words is "one billion, six hundred sixty-five million, seven hundred twenty-three thousand, five hundred twenty-eight".