21001373203 has 2 divisors, whose sum is σ = 21001373204. Its totient is φ = 21001373202.

The previous prime is 21001373201. The next prime is 21001373251. The reversal of 21001373203 is 30237310012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21001373203 - 2¹ = 21001373201 is a prime.

Together with 21001373201, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21001373201) 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 as a sum of consecutive naturals, namely, 10500686601 + 10500686602.

It is an arithmetic number, because the mean of its divisors is an integer number (10500686602).

Almost surely, 2^21001373203 is an apocalyptic number.

21001373203 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001373203 is an equidigital number, since it uses as much as digits as its factorization.

21001373203 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 22.

Adding to 21001373203 its reverse (30237310012), we get a palindrome (51238683215).

The spelling of 21001373203 in words is "twenty-one billion, one million, three hundred seventy-three thousand, two hundred three".