921921800 has 108 divisors (see below), whose sum is σ = 2282416695. Its totient is φ = 346268160.

The previous prime is 921921799. The next prime is 921921817. The reversal of 921921800 is 8129129.

It is a happy number.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

921921800 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 5 ways, for example, as 70756 + 921851044 = 266^2 + 30362^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=21470.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 8158544 + ... + 8158656.

Almost surely, 2^921921800 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 921921800

921921800 is an abundant number, since it is smaller than the sum of its proper divisors (1360494895).

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

921921800 is a wasteful number, since it uses less digits than its factorization.

921921800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280 (or 139 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 921921800 is about 30363.1651841504. The cubic root of 921921800 is about 973.2655730440.

Multiplying 921921800 by its sum of digits (32), we get a square (29501497600 = 171760²).

Multiplying 921921800 by its product of nonzero digits (2592), we get a square (2389621305600 = 1545840²).

The spelling of 921921800 in words is "nine hundred twenty-one million, nine hundred twenty-one thousand, eight hundred".