21203321201 has 4 divisors (see below), whose sum is σ = 21320466804. Its totient is φ = 21086175600.

The previous prime is 21203321189. The next prime is 21203321231. The reversal of 21203321201 is 10212330212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8222136976 + 12981184225 = 90676^2 + 113935^2 .

It is a cyclic number.

It is not a de Polignac number, because 21203321201 - 2⁶ = 21203321137 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21203321201.

It is not an unprimeable number, because it can be changed into a prime (21203321231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58572530 + ... + 58572891.

It is an arithmetic number, because the mean of its divisors is an integer number (5330116701).

Almost surely, 2^21203321201 is an apocalyptic number.

It is an amenable number.

21203321201 is a deficient number, since it is larger than the sum of its proper divisors (117145603).

21203321201 is a wasteful number, since it uses less digits than its factorization.

21203321201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117145602.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21203321201 its reverse (10212330212), we get a palindrome (31415651413).

The spelling of 21203321201 in words is "twenty-one billion, two hundred three million, three hundred twenty-one thousand, two hundred one".