400421 has 4 divisors (see below), whose sum is σ = 457632. Its totient is φ = 343212.

The previous prime is 400417. The next prime is 400429. The reversal of 400421 is 124004.

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 400421 - 2² = 400417 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28595 + ... + 28608.

It is an arithmetic number, because the mean of its divisors is an integer number (114408).

2⁴⁰⁰⁴²¹ is an apocalyptic number.

It is an amenable number.

400421 is a deficient number, since it is larger than the sum of its proper divisors (57211).

400421 is an equidigital number, since it uses as much as digits as its factorization.

400421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57210.

The product of its (nonzero) digits is 32, while the sum is 11.

The square root of 400421 is about 632.7882742276. The cubic root of 400421 is about 73.7064705302.

Adding to 400421 its reverse (124004), we get a palindrome (524425).

The spelling of 400421 in words is "four hundred thousand, four hundred twenty-one", and thus it is an iban number.