21042242201 has 4 divisors (see below), whose sum is σ = 22280021172. Its totient is φ = 19804463232.

The previous prime is 21042242191. The next prime is 21042242219. The reversal of 21042242201 is 10224224012.

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 7891657225 + 13150584976 = 88835^2 + 114676^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21042242201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21042212201) 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, 618889460 + ... + 618889493.

It is an arithmetic number, because the mean of its divisors is an integer number (5570005293).

Almost surely, 2^21042242201 is an apocalyptic number.

It is an amenable number.

21042242201 is a deficient number, since it is larger than the sum of its proper divisors (1237778971).

21042242201 is a wasteful number, since it uses less digits than its factorization.

21042242201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1237778970.

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21042242201 its reverse (10224224012), we get a palindrome (31266466213).

The spelling of 21042242201 in words is "twenty-one billion, forty-two million, two hundred forty-two thousand, two hundred one".