1664549208 has 144 divisors (see below), whose sum is σ = 5266553760. Its totient is φ = 473558400.

The previous prime is 1664549177. The next prime is 1664549219. The reversal of 1664549208 is 8029454661.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 955218 + ... + 956958.

It is an arithmetic number, because the mean of its divisors is an integer number (36573290).

Almost surely, 2^1664549208 is an apocalyptic number.

1664549208 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 1664549208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2633276880).

1664549208 is an abundant number, since it is smaller than the sum of its proper divisors (3602004552).

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

1664549208 is a wasteful number, since it uses less digits than its factorization.

1664549208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2038 (or 2024 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The square root of 1664549208 is about 40798.8873377694. The cubic root of 1664549208 is about 1185.1287837389.

The spelling of 1664549208 in words is "one billion, six hundred sixty-four million, five hundred forty-nine thousand, two hundred eight".