1680209920 has 192 divisors, whose sum is σ = 4277145600. Its totient is φ = 632586240.

The previous prime is 1680209903. The next prime is 1680209939. The reversal of 1680209920 is 299020861.

It is a self number, because there is not a number n which added to its sum of digits gives 1680209920.

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, 21268441 + ... + 21268519.

It is an arithmetic number, because the mean of its divisors is an integer number (22276800).

Almost surely, 2^1680209920 is an apocalyptic number.

1680209920 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 1680209920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2138572800).

1680209920 is an abundant number, since it is smaller than the sum of its proper divisors (2596935680).

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

1680209920 is an equidigital number, since it uses as much as digits as its factorization.

1680209920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204 (or 184 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 1680209920 is about 40990.3637456415. The cubic root of 1680209920 is about 1188.8339023038.

It can be divided in two parts, 1680 and 209920, that added together give a square (211600 = 460²).

The spelling of 1680209920 in words is "one billion, six hundred eighty million, two hundred nine thousand, nine hundred twenty".