21333133121 has 4 divisors (see below), whose sum is σ = 22260660672. Its totient is φ = 20405605572.

The previous prime is 21333133099. The next prime is 21333133123. The reversal of 21333133121 is 12133133312.

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 not a de Polignac number, because 21333133121 - 2¹⁴ = 21333116737 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 927527527 = 21333133121 / (2 + 1 + 3 + 3 + 3 + 1 + 3 + 3 + 1 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21333133123) 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, 463763741 + ... + 463763786.

It is an arithmetic number, because the mean of its divisors is an integer number (5565165168).

Almost surely, 2^21333133121 is an apocalyptic number.

It is an amenable number.

21333133121 is a deficient number, since it is larger than the sum of its proper divisors (927527551).

21333133121 is an equidigital number, since it uses as much as digits as its factorization.

21333133121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 927527550.

The product of its digits is 972, while the sum is 23.

Adding to 21333133121 its reverse (12133133312), we get a palindrome (33466266433).

The spelling of 21333133121 in words is "twenty-one billion, three hundred thirty-three million, one hundred thirty-three thousand, one hundred twenty-one".