1665443264 has 56 divisors (see below), whose sum is σ = 3356152800. Its totient is φ = 819901440.

The previous prime is 1665443257. The next prime is 1665443293. The reversal of 1665443264 is 4623445661.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1261997 + ... + 1263315.

It is an arithmetic number, because the mean of its divisors is an integer number (59931300).

Almost surely, 2^1665443264 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1665443264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1678076400).

1665443264 is an abundant number, since it is smaller than the sum of its proper divisors (1690709536).

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

1665443264 is a wasteful number, since it uses less digits than its factorization.

1665443264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1621 (or 1611 counting only the distinct ones).

The product of its digits is 414720, while the sum is 41.

The square root of 1665443264 is about 40809.8427343208. The cubic root of 1665443264 is about 1185.3409296354.

The spelling of 1665443264 in words is "one billion, six hundred sixty-five million, four hundred forty-three thousand, two hundred sixty-four".