40421 has 4 divisors (see below), whose sum is σ = 40992. Its totient is φ = 39852.

The previous prime is 40387. The next prime is 40423. The reversal of 40421 is 12404.

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 40421 - 2⁶ = 40357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40423) 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, 161 + ... + 326.

It is an arithmetic number, because the mean of its divisors is an integer number (10248).

2⁴⁰⁴²¹ is an apocalyptic number.

It is an amenable number.

40421 is a deficient number, since it is larger than the sum of its proper divisors (571).

40421 is an equidigital number, since it uses as much as digits as its factorization.

40421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570.

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

The square root of 40421 is about 201.0497450881. The cubic root of 40421 is about 34.3190837485.

Adding to 40421 its reverse (12404), we get a palindrome (52825).

The spelling of 40421 in words is "forty thousand, four hundred twenty-one", and thus it is an iban number.