400400400040 has 32 divisors (see below), whose sum is σ = 901082724480. Its totient is φ = 160127835712.

The previous prime is 400400400031. The next prime is 400400400041. The reversal of 400400400040 is 40004004004.

It is a junction number, because it is equal to n+sod(n) for n = 400400399987 and 400400400023.

It is not an unprimeable number, because it can be changed into a prime (400400400041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 808972 + ... + 1206331.

It is an arithmetic number, because the mean of its divisors is an integer number (28158835140).

Almost surely, 2^400400400040 is an apocalyptic number.

400400400040 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400400400040 is an abundant number, since it is smaller than the sum of its proper divisors (500682324440).

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

400400400040 is a wasteful number, since it uses less digits than its factorization.

400400400040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2020281 (or 2020277 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 16.

Adding to 400400400040 its reverse (40004004004), we get a palindrome (440404404044).

The spelling of 400400400040 in words is "four hundred billion, four hundred million, four hundred thousand, forty".