20413221 has 16 divisors (see below), whose sum is σ = 28262400. Its totient is φ = 13091760.

The previous prime is 20413219. The next prime is 20413231. The reversal of 20413221 is 12231402.

It is not a de Polignac number, because 20413221 - 2¹ = 20413219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20413221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20413231) 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, 17956 + ... + 19058.

It is an arithmetic number, because the mean of its divisors is an integer number (1766400).

Almost surely, 2^20413221 is an apocalyptic number.

It is an amenable number.

20413221 is a deficient number, since it is larger than the sum of its proper divisors (7849179).

20413221 is a wasteful number, since it uses less digits than its factorization.

20413221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1336.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 20413221 is about 4518.0992684978. The cubic root of 20413221 is about 273.2984566181.

Adding to 20413221 its reverse (12231402), we get a palindrome (32644623).

The spelling of 20413221 in words is "twenty million, four hundred thirteen thousand, two hundred twenty-one".