400810221 has 32 divisors (see below), whose sum is σ = 691441920. Its totient is φ = 224707392.

The previous prime is 400810171. The next prime is 400810243. The reversal of 400810221 is 122018004.

It is not a de Polignac number, because 400810221 - 2⁹ = 400809709 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 400810194 and 400810203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400810271) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9990 + ... + 30023.

It is an arithmetic number, because the mean of its divisors is an integer number (21607560).

Almost surely, 2^400810221 is an apocalyptic number.

It is an amenable number.

400810221 is a deficient number, since it is larger than the sum of its proper divisors (290631699).

400810221 is a wasteful number, since it uses less digits than its factorization.

400810221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40082 (or 40076 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 400810221 is about 20020.2452782177. The cubic root of 400810221 is about 737.3034441624.

Adding to 400810221 its reverse (122018004), we get a palindrome (522828225).

The spelling of 400810221 in words is "four hundred million, eight hundred ten thousand, two hundred twenty-one".