921449840 has 80 divisors (see below), whose sum is σ = 2263917600. Its totient is φ = 347821056.

The previous prime is 921449839. The next prime is 921449843. The reversal of 921449840 is 48944129.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (921449843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 444326 + ... + 446394.

It is an arithmetic number, because the mean of its divisors is an integer number (28298970).

Almost surely, 2^921449840 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 921449840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1131958800).

921449840 is an abundant number, since it is smaller than the sum of its proper divisors (1342467760).

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

921449840 is a wasteful number, since it uses less digits than its factorization.

921449840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2394 (or 2388 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 921449840 is about 30355.3922722142. The cubic root of 921449840 is about 973.0994632119.

The spelling of 921449840 in words is "nine hundred twenty-one million, four hundred forty-nine thousand, eight hundred forty".