21203220001 has 4 divisors (see below), whose sum is σ = 21203572500. Its totient is φ = 21202867504.

The previous prime is 21203219953. The next prime is 21203220007. The reversal of 21203220001 is 10002230212.

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 16978090000 + 4225130001 = 130300^2 + 65001^2 .

It is a cyclic number.

It is not a de Polignac number, because 21203220001 - 2³³ = 12613285409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21203220007) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60826 + ... + 214723.

It is an arithmetic number, because the mean of its divisors is an integer number (5300893125).

Almost surely, 2^21203220001 is an apocalyptic number.

It is an amenable number.

21203220001 is a deficient number, since it is larger than the sum of its proper divisors (352499).

21203220001 is an equidigital number, since it uses as much as digits as its factorization.

21203220001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352498.

The product of its (nonzero) digits is 48, while the sum is 13.

Adding to 21203220001 its reverse (10002230212), we get a palindrome (31205450213).

The spelling of 21203220001 in words is "twenty-one billion, two hundred three million, two hundred twenty thousand, one".