864919440 has 240 divisors, whose sum is σ = 3621661056. Its totient is φ = 179712000.

The previous prime is 864919423. The next prime is 864919453. The reversal of 864919440 is 44919468.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 47640 + ... + 63240.

Almost surely, 2^864919440 is an apocalyptic number.

864919440 is a gapful number since it is divisible by the number (80) 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 864919440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1810830528).

864919440 is an abundant number, since it is smaller than the sum of its proper divisors (2756741616).

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

864919440 is a wasteful number, since it uses less digits than its factorization.

864919440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15638 (or 15629 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The square root of 864919440 is about 29409.5127467287. The cubic root of 864919440 is about 952.7783632654.

The spelling of 864919440 in words is "eight hundred sixty-four million, nine hundred nineteen thousand, four hundred forty".