400431220 has 24 divisors (see below), whose sum is σ = 961035264. Its totient is φ = 137290656.

The previous prime is 400431197. The next prime is 400431233. The reversal of 400431220 is 22134004.

It is a junction number, because it is equal to n+sod(n) for n = 400431194 and 400431203.

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, 1429972 + ... + 1430251.

It is an arithmetic number, because the mean of its divisors is an integer number (40043136).

Almost surely, 2^400431220 is an apocalyptic number.

It is an amenable number.

400431220 is an abundant number, since it is smaller than the sum of its proper divisors (560604044).

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

400431220 is a wasteful number, since it uses less digits than its factorization.

400431220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2860239 (or 2860237 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 400431220 is about 20010.7775960856. Note that the first 3 decimals coincide. The cubic root of 400431220 is about 737.0709759832.

Adding to 400431220 its reverse (22134004), we get a palindrome (422565224).

The spelling of 400431220 in words is "four hundred million, four hundred thirty-one thousand, two hundred twenty".