400221421 has 4 divisors (see below), whose sum is σ = 400615200. Its totient is φ = 399827644.

The previous prime is 400221407. The next prime is 400221473. The reversal of 400221421 is 124122004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 400221421 - 2¹¹ = 400219373 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 400221395 and 400221404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400221221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 195361 + ... + 197398.

It is an arithmetic number, because the mean of its divisors is an integer number (100153800).

Almost surely, 2^400221421 is an apocalyptic number.

It is an amenable number.

400221421 is a deficient number, since it is larger than the sum of its proper divisors (393779).

400221421 is a wasteful number, since it uses less digits than its factorization.

400221421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393778.

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

The square root of 400221421 is about 20005.5347591610. The cubic root of 400221421 is about 736.9422283064.

Adding to 400221421 its reverse (124122004), we get a palindrome (524343425).

The spelling of 400221421 in words is "four hundred million, two hundred twenty-one thousand, four hundred twenty-one".