400855840 has 96 divisors (see below), whose sum is σ = 1180738944. Its totient is φ = 124938240.

The previous prime is 400855781. The next prime is 400855859. The reversal of 400855840 is 48558004.

It is a junction number, because it is equal to n+sod(n) for n = 400855796 and 400855805.

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 15 ways as a sum of consecutive naturals, for example, 3949 + ... + 28588.

It is an arithmetic number, because the mean of its divisors is an integer number (12299364).

Almost surely, 2^400855840 is an apocalyptic number.

400855840 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 400855840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (590369472).

400855840 is an abundant number, since it is smaller than the sum of its proper divisors (779883104).

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

400855840 is a wasteful number, since it uses less digits than its factorization.

400855840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32570 (or 32562 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 34.

The square root of 400855840 is about 20021.3845675068. The cubic root of 400855840 is about 737.3314156462.

The spelling of 400855840 in words is "four hundred million, eight hundred fifty-five thousand, eight hundred forty".