400400404220 has 24 divisors (see below), whose sum is σ = 840857889984. Its totient is φ = 160156915776.

The previous prime is 400400404207. The next prime is 400400404289. The reversal of 400400404220 is 22404004004.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 400400404192 and 400400404201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 975614 + ... + 1323866.

It is an arithmetic number, because the mean of its divisors is an integer number (35035745416).

Almost surely, 2^400400404220 is an apocalyptic number.

It is an amenable number.

400400404220 is an abundant number, since it is smaller than the sum of its proper divisors (440457485764).

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

400400404220 is a wasteful number, since it uses less digits than its factorization.

400400404220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405749 (or 405747 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 20.

Adding to 400400404220 its reverse (22404004004), we get a palindrome (422804408224).

The spelling of 400400404220 in words is "four hundred billion, four hundred million, four hundred four thousand, two hundred twenty".