915421440 has 288 divisors, whose sum is σ = 3187658880. Its totient is φ = 222953472.

The previous prime is 915421439. The next prime is 915421471. The reversal of 915421440 is 44124519.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 915421398 and 915421407.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2415171 + ... + 2415549.

It is an arithmetic number, because the mean of its divisors is an integer number (11068260).

Almost surely, 2^915421440 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 915421440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1593829440).

915421440 is an abundant number, since it is smaller than the sum of its proper divisors (2272237440).

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

915421440 is a wasteful number, since it uses less digits than its factorization.

915421440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457 (or 443 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 915421440 is about 30255.9323108709. The cubic root of 915421440 is about 970.9727160895.

Adding to 915421440 its reverse (44124519), we get a palindrome (959545959).

The spelling of 915421440 in words is "nine hundred fifteen million, four hundred twenty-one thousand, four hundred forty".