21003121133 has 4 divisors (see below), whose sum is σ = 21003693120. Its totient is φ = 21002549148.

The previous prime is 21003121123. The next prime is 21003121141. The reversal of 21003121133 is 33112130012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21003121133 is a prime.

It is a super-2 number, since 2×21003121133² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003121123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 226835 + ... + 305712.

It is an arithmetic number, because the mean of its divisors is an integer number (5250923280).

Almost surely, 2^21003121133 is an apocalyptic number.

It is an amenable number.

21003121133 is a deficient number, since it is larger than the sum of its proper divisors (571987).

21003121133 is an equidigital number, since it uses as much as digits as its factorization.

21003121133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571986.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 21003121133 its reverse (33112130012), we get a palindrome (54115251145).

The spelling of 21003121133 in words is "twenty-one billion, three million, one hundred twenty-one thousand, one hundred thirty-three".