400435220 has 24 divisors (see below), whose sum is σ = 841290408. Its totient is φ = 160102400.

The previous prime is 400435213. The next prime is 400435229. The reversal of 400435220 is 22534004.

It can be written as a sum of positive squares in 4 ways, for example, as 155700484 + 244734736 = 12478^2 + 15644^2 .

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 = 400435192 and 400435201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400435229) 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, 82460 + ... + 87180.

It is an arithmetic number, because the mean of its divisors is an integer number (35053767).

Almost surely, 2^400435220 is an apocalyptic number.

It is an amenable number.

400435220 is an abundant number, since it is smaller than the sum of its proper divisors (440855188).

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

400435220 is a wasteful number, since it uses less digits than its factorization.

400435220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8971 (or 8969 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 20.

The square root of 400435220 is about 20010.8775419770. The cubic root of 400435220 is about 737.0734302325.

Adding to 400435220 its reverse (22534004), we get a palindrome (422969224).

The spelling of 400435220 in words is "four hundred million, four hundred thirty-five thousand, two hundred twenty".