400412221 has 16 divisors (see below), whose sum is σ = 456611328. Its totient is φ = 347569200.

The previous prime is 400412171. The next prime is 400412231. The reversal of 400412221 is 122214004.

It is not a de Polignac number, because 400412221 - 2¹⁹ = 399887933 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 400412195 and 400412204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400412231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 198106 + ... + 200116.

It is an arithmetic number, because the mean of its divisors is an integer number (28538208).

Almost surely, 2^400412221 is an apocalyptic number.

It is an amenable number.

400412221 is a deficient number, since it is larger than the sum of its proper divisors (56199107).

400412221 is a wasteful number, since it uses less digits than its factorization.

400412221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2832.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 400412221 is about 20010.3028712711. The cubic root of 400412221 is about 737.0593186896.

Adding to 400412221 its reverse (122214004), we get a palindrome (522626225).

The spelling of 400412221 in words is "four hundred million, four hundred twelve thousand, two hundred twenty-one".