409940640 has 72 divisors (see below), whose sum is σ = 1398927348. Its totient is φ = 109317120.

The previous prime is 409940611. The next prime is 409940651. The reversal of 409940640 is 46049904.

409940640 is a `hidden beast` number, since 4 + 0 + 9 + 9 + 4 + 0 + 640 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 409819536 + 121104 = 20244^2 + 348^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 409940595 and 409940604.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 140901 + ... + 143780.

Almost surely, 2^409940640 is an apocalyptic number.

409940640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

409940640 is an abundant number, since it is smaller than the sum of its proper divisors (988986708).

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

409940640 is a wasteful number, since it uses less digits than its factorization.

409940640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284702 (or 284691 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 409940640 is about 20246.9908875368. The cubic root of 409940640 is about 742.8600301381.

The spelling of 409940640 in words is "four hundred nine million, nine hundred forty thousand, six hundred forty".