21533343205511 has 4 divisors (see below), whose sum is σ = 22800010452912. Its totient is φ = 20266675958112.

The previous prime is 21533343205433. The next prime is 21533343205559. The reversal of 21533343205511 is 11550234333512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21533343205511 - 2²² = 21533339011207 is a prime.

It is a super-2 number, since 2×21533343205511² (a number of 27 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 (21533343235511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 633333623675 + ... + 633333623708.

It is an arithmetic number, because the mean of its divisors is an integer number (5700002613228).

Almost surely, 2^{21533343205511} is an apocalyptic number.

21533343205511 is a deficient number, since it is larger than the sum of its proper divisors (1266667247401).

21533343205511 is a wasteful number, since it uses less digits than its factorization.

21533343205511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1266667247400.

The product of its (nonzero) digits is 162000, while the sum is 38.

The spelling of 21533343205511 in words is "twenty-one trillion, five hundred thirty-three billion, three hundred forty-three million, two hundred five thousand, five hundred eleven".