21042111133 has 4 divisors (see below), whose sum is σ = 21043015708. Its totient is φ = 21041206560.

The previous prime is 21042111091. The next prime is 21042111161. The reversal of 21042111133 is 33111124012.

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 16466535684 + 4575575449 = 128322^2 + 67643^2 .

It is a cyclic number.

It is not a de Polignac number, because 21042111133 - 2¹³ = 21042102941 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21042111133.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21042118133) 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, 416448 + ... + 464233.

It is an arithmetic number, because the mean of its divisors is an integer number (5260753927).

Almost surely, 2^21042111133 is an apocalyptic number.

It is an amenable number.

21042111133 is a deficient number, since it is larger than the sum of its proper divisors (904575).

21042111133 is an equidigital number, since it uses as much as digits as its factorization.

21042111133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 904574.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 21042111133 its reverse (33111124012), we get a palindrome (54153235145).

The spelling of 21042111133 in words is "twenty-one billion, forty-two million, one hundred eleven thousand, one hundred thirty-three".