400808840 has 32 divisors (see below), whose sum is σ = 903999960. Its totient is φ = 159936000.

The previous prime is 400808831. The next prime is 400808897. The reversal of 400808840 is 48808004.

It can be written as a sum of positive squares in 4 ways, for example, as 237838084 + 162970756 = 15422^2 + 12766^2 .

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 400808797 and 400808806.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4940 + ... + 28740.

Almost surely, 2^400808840 is an apocalyptic number.

400808840 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400808840 is an abundant number, since it is smaller than the sum of its proper divisors (503191120).

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

400808840 is a wasteful number, since it uses less digits than its factorization.

400808840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24233 (or 24229 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 32.

The square root of 400808840 is about 20020.2107881011. The cubic root of 400808840 is about 737.3025973633.

The spelling of 400808840 in words is "four hundred million, eight hundred eight thousand, eight hundred forty".