1005640440 has 128 divisors (see below), whose sum is σ = 3650780160. Its totient is φ = 216336384.

The previous prime is 1005640439. The next prime is 1005640487. The reversal of 1005640440 is 440465001.

It is a super-2 number, since 2×1005640440² = 2022625389126787200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1005640440.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20932 + ... + 49491.

It is an arithmetic number, because the mean of its divisors is an integer number (28521720).

Almost surely, 2^1005640440 is an apocalyptic number.

1005640440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1005640440 is an abundant number, since it is smaller than the sum of its proper divisors (2645139720).

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

1005640440 is a wasteful number, since it uses less digits than its factorization.

1005640440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70461 (or 70457 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 1005640440 is about 31711.8343840277. The cubic root of 1005640440 is about 1001.8766227507.

The spelling of 1005640440 in words is "one billion, five million, six hundred forty thousand, four hundred forty".