408576640 has 144 divisors (see below), whose sum is σ = 1060135470. Its totient is φ = 150544384.

The previous prime is 408576631. The next prime is 408576667. The reversal of 408576640 is 46675804.

It can be written as a sum of positive squares in 3 ways, for example, as 397125184 + 11451456 = 19928^2 + 3384^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 408576593 and 408576602.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 8693097 + ... + 8693143.

Almost surely, 2^408576640 is an apocalyptic number.

408576640 is a gapful number since it is divisible by the number (40) 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 408576640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (530067735).

408576640 is an abundant number, since it is smaller than the sum of its proper divisors (651558830).

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

408576640 is an equidigital number, since it uses as much as digits as its factorization.

408576640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 40.

The square root of 408576640 is about 20213.2788037963. The cubic root of 408576640 is about 742.0352058622.

Multiplying 408576640 by its sum of digits (40), we get a square (16343065600 = 127840²).

408576640 divided by its sum of digits (40) gives a square (10214416 = 3196²).

The spelling of 408576640 in words is "four hundred eight million, five hundred seventy-six thousand, six hundred forty".