921790320 has 640 divisors, whose sum is σ = 3702620160. Its totient is φ = 186531840.

The previous prime is 921790313. The next prime is 921790333. The reversal of 921790320 is 23097129.

It is a Cunningham number, because it is equal to 30361²-1.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 19612537 + ... + 19612583.

It is an arithmetic number, because the mean of its divisors is an integer number (5785344).

Almost surely, 2^921790320 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 921790320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1851310080).

921790320 is an abundant number, since it is smaller than the sum of its proper divisors (2780829840).

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

921790320 is a wasteful number, since it uses less digits than its factorization.

921790320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133 (or 127 counting only the distinct ones).

The product of its (nonzero) digits is 6804, while the sum is 33.

The square root of 921790320 is about 30360.9999835315. Note that the first 4 decimals coincide. The cubic root of 921790320 is about 973.2193033780.

The spelling of 921790320 in words is "nine hundred twenty-one million, seven hundred ninety thousand, three hundred twenty".