1664375328 has 216 divisors, whose sum is σ = 5946542784. Its totient is φ = 432241920.

The previous prime is 1664375311. The next prime is 1664375351. The reversal of 1664375328 is 8235734661.

1664375328 is a `hidden beast` number, since 166 + 437 + 53 + 2 + 8 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 240525 + ... + 247347.

Almost surely, 2^1664375328 is an apocalyptic number.

1664375328 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 1664375328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2973271392).

1664375328 is an abundant number, since it is smaller than the sum of its proper divisors (4282167456).

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

1664375328 is a wasteful number, since it uses less digits than its factorization.

1664375328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6868 (or 6846 counting only the distinct ones).

The product of its digits is 725760, while the sum is 45.

The square root of 1664375328 is about 40796.7563416505. The cubic root of 1664375328 is about 1185.0875158353.

The spelling of 1664375328 in words is "one billion, six hundred sixty-four million, three hundred seventy-five thousand, three hundred twenty-eight".