21540133353 has 4 divisors (see below), whose sum is σ = 28720177808. Its totient is φ = 14360088900.

The previous prime is 21540133333. The next prime is 21540133367. The reversal of 21540133353 is 35333104512.

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 not a de Polignac number, because 21540133353 - 2⁹ = 21540132841 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21540133353.

It is not an unprimeable number, because it can be changed into a prime (21540133333) 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, 3590022223 + ... + 3590022228.

It is an arithmetic number, because the mean of its divisors is an integer number (7180044452).

Almost surely, 2^21540133353 is an apocalyptic number.

It is an amenable number.

21540133353 is a deficient number, since it is larger than the sum of its proper divisors (7180044455).

21540133353 is an equidigital number, since it uses as much as digits as its factorization.

21540133353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7180044454.

The product of its (nonzero) digits is 16200, while the sum is 30.

Adding to 21540133353 its reverse (35333104512), we get a palindrome (56873237865).

The spelling of 21540133353 in words is "twenty-one billion, five hundred forty million, one hundred thirty-three thousand, three hundred fifty-three".