21203122001 has 4 divisors (see below), whose sum is σ = 21413054004. Its totient is φ = 20993190000.

The previous prime is 21203121967. The next prime is 21203122009. The reversal of 21203122001 is 10022130212.

It is a happy number.

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 19902437776 + 1300684225 = 141076^2 + 36065^2 .

It is a cyclic number.

It is not a de Polignac number, because 21203122001 - 2²⁶ = 21136013137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21203122009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104965850 + ... + 104966051.

It is an arithmetic number, because the mean of its divisors is an integer number (5353263501).

Almost surely, 2^21203122001 is an apocalyptic number.

It is an amenable number.

21203122001 is a deficient number, since it is larger than the sum of its proper divisors (209932003).

21203122001 is a wasteful number, since it uses less digits than its factorization.

21203122001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209932002.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21203122001 its reverse (10022130212), we get a palindrome (31225252213).

The spelling of 21203122001 in words is "twenty-one billion, two hundred three million, one hundred twenty-two thousand, one".