21020201 has 8 divisors (see below), whose sum is σ = 21758208.
Its totient is φ = 20286000.
The previous prime is 21020161. The next prime is 21020227. The reversal of 21020201 is 10202012.
It is a sphenic number, since it is the product of 3 distinct primes.
It is a cyclic number.
It is not a de Polignac number, because 21020201 - 210 = 21019177 is a prime.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (21020231) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14531 + ... + 15911.
It is an arithmetic number, because the mean of its divisors is an integer number (2719776).
Almost surely, 221020201 is an apocalyptic number.
It is an amenable number.
21020201 is a deficient number, since it is larger than the sum of its proper divisors (738007).
21020201 is a wasteful number, since it uses less digits than its factorization.
21020201 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 1903.
The product of its (nonzero) digits is 8, while the sum is 8.
The square root of 21020201 is about 4584.7792749488.
The cubic root of 21020201 is about 275.9808544095.
Adding to 21020201 its reverse (10202012), we get a palindrome (31222213).
It can be divided in two parts, 2 and 1020201, that multiplied together give a palindrome (2040402).
The spelling of 21020201 in words is "twenty-one million, twenty thousand, two hundred one".