20102221 has 4 divisors (see below), whose sum is σ = 20115072.
Its totient is φ = 20089372.
The previous prime is 20102219. The next prime is 20102227. The reversal of 20102221 is 12220102.
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 20102221 - 21 = 20102219 is a prime.
It is a Duffinian number.
It is a junction number, because it is equal to n+sod(n) for n = 20102198 and 20102207.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (20102227) 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, 3691 + ... + 7336.
It is an arithmetic number, because the mean of its divisors is an integer number (5028768).
Almost surely, 220102221 is an apocalyptic number.
It is an amenable number.
20102221 is a deficient number, since it is larger than the sum of its proper divisors (12851).
20102221 is a wasteful number, since it uses less digits than its factorization.
20102221 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 12850.
The product of its (nonzero) digits is 16, while the sum is 10.
The square root of 20102221 is about 4483.5500443287.
The cubic root of 20102221 is about 271.9034268246.
Adding to 20102221 its reverse (12220102), we get a palindrome (32322323).
The spelling of 20102221 in words is "twenty million, one hundred two thousand, two hundred twenty-one".