199921920 has 144 divisors (see below), whose sum is σ = 696693312. Its totient is φ = 48455680.

The previous prime is 199921919. The next prime is 199921937. The reversal of 199921920 is 29129991.

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, 39874 + ... + 44606.

It is an arithmetic number, because the mean of its divisors is an integer number (4838148).

Almost surely, 2^199921920 is an apocalyptic number.

199921920 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 199921920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (348346656).

199921920 is an abundant number, since it is smaller than the sum of its proper divisors (496771392).

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

199921920 is a wasteful number, since it uses less digits than its factorization.

199921920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4768 (or 4754 counting only the distinct ones).

The product of its (nonzero) digits is 26244, while the sum is 42.

The square root of 199921920 is about 14139.3748093754. The cubic root of 199921920 is about 584.7274353020.

It can be divided in two parts, 19992 and 1920, that added together give a palindrome (21912).

The spelling of 199921920 in words is "one hundred ninety-nine million, nine hundred twenty-one thousand, nine hundred twenty".