1004005440 has 168 divisors, whose sum is σ = 3493053720. Its totient is φ = 264658944.

The previous prime is 1004005439. The next prime is 1004005469. The reversal of 1004005440 is 445004001.

It can be written as a sum of positive squares in 4 ways, for example, as 101123136 + 902882304 = 10056^2 + 30048^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 254362 + ... + 258278.

Almost surely, 2^1004005440 is an apocalyptic number.

1004005440 is a gapful number since it is divisible by the number (10) 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 1004005440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1746526860).

1004005440 is an abundant number, since it is smaller than the sum of its proper divisors (2489048280).

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

1004005440 is a wasteful number, since it uses less digits than its factorization.

1004005440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4029 (or 4016 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 1004005440 is about 31686.0448778323. The cubic root of 1004005440 is about 1001.3333680062. Note that the first 4 decimals are identical.

Adding to 1004005440 its reverse (445004001), we get a palindrome (1449009441).

The spelling of 1004005440 in words is "one billion, four million, five thousand, four hundred forty".