1664880 has 80 divisors (see below), whose sum is σ = 5904384. Its totient is φ = 380160.

The previous prime is 1664869. The next prime is 1664893. The reversal of 1664880 is 884661.

It is a tau number, because it is divible by the number of its divisors (80).

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1185 + ... + 2175.

2^1664880 is an apocalyptic number.

1664880 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 1664880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2952192).

1664880 is an abundant number, since it is smaller than the sum of its proper divisors (4239504).

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

1664880 is a wasteful number, since it uses less digits than its factorization.

1664880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1014 (or 1008 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 1664880 is about 1290.3022901630. The cubic root of 1664880 is about 118.5207284503.

The spelling of 1664880 in words is "one million, six hundred sixty-four thousand, eight hundred eighty".