40021221 has 4 divisors (see below), whose sum is σ = 53361632. Its totient is φ = 26680812.

The previous prime is 40021211. The next prime is 40021231. The reversal of 40021221 is 12212004.

40021221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 an interprime number because it is at equal distance from previous prime (40021211) and next prime (40021231).

It is a de Polignac number, because none of the positive numbers 2^k-40021221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40021197 and 40021206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40021211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6670201 + ... + 6670206.

It is an arithmetic number, because the mean of its divisors is an integer number (13340408).

Almost surely, 2^40021221 is an apocalyptic number.

It is an amenable number.

40021221 is a deficient number, since it is larger than the sum of its proper divisors (13340411).

40021221 is a wasteful number, since it uses less digits than its factorization.

40021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13340410.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 40021221 is about 6326.2327652403. The cubic root of 40021221 is about 342.0556576426.

Adding to 40021221 its reverse (12212004), we get a palindrome (52233225).

The spelling of 40021221 in words is "forty million, twenty-one thousand, two hundred twenty-one".