1664330988 has 12 divisors (see below), whose sum is σ = 3883439000. Its totient is φ = 554776992.

The previous prime is 1664330981. The next prime is 1664330989. The reversal of 1664330988 is 8890334661.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×1664330988² = 5539995275234112288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1664330981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69347113 + ... + 69347136.

Almost surely, 2^1664330988 is an apocalyptic number.

It is an amenable number.

1664330988 is an abundant number, since it is smaller than the sum of its proper divisors (2219108012).

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

1664330988 is a wasteful number, since it uses less digits than its factorization.

1664330988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138694256 (or 138694254 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 48.

The square root of 1664330988 is about 40796.2129124751. The cubic root of 1664330988 is about 1185.0769919176.

The spelling of 1664330988 in words is "one billion, six hundred sixty-four million, three hundred thirty thousand, nine hundred eighty-eight".