1664673920 has 256 divisors, whose sum is σ = 4963956480. Its totient is φ = 519782400.

The previous prime is 1664673877. The next prime is 1664673937. The reversal of 1664673920 is 293764661.

It is a super-2 number, since 2×1664673920² = 5542278519856332800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5882099 + ... + 5882381.

It is an arithmetic number, because the mean of its divisors is an integer number (19390455).

Almost surely, 2^1664673920 is an apocalyptic number.

1664673920 is a gapful number since it is divisible by the number (10) 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 1664673920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2481978240).

1664673920 is an abundant number, since it is smaller than the sum of its proper divisors (3299282560).

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

1664673920 is a wasteful number, since it uses less digits than its factorization.

1664673920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423 (or 411 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 44.

The square root of 1664673920 is about 40800.4156841569. The cubic root of 1664673920 is about 1185.1583805589.

The spelling of 1664673920 in words is "one billion, six hundred sixty-four million, six hundred seventy-three thousand, nine hundred twenty".