21133535405 has 8 divisors (see below), whose sum is σ = 25707643512. Its totient is φ = 16675227648.

The previous prime is 21133535399. The next prime is 21133535407. The reversal of 21133535405 is 50453533112.

It can be written as a sum of positive squares in 4 ways, for example, as 2317652164 + 18815883241 = 48142^2 + 137171^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21133535405 - 2⁴ = 21133535389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21133535407) 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 7 ways as a sum of consecutive naturals, for example, 28949684 + ... + 28950413.

It is an arithmetic number, because the mean of its divisors is an integer number (3213455439).

Almost surely, 2^21133535405 is an apocalyptic number.

It is an amenable number.

21133535405 is a deficient number, since it is larger than the sum of its proper divisors (4574108107).

21133535405 is an equidigital number, since it uses as much as digits as its factorization.

21133535405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57900175.

The product of its (nonzero) digits is 27000, while the sum is 32.

The spelling of 21133535405 in words is "twenty-one billion, one hundred thirty-three million, five hundred thirty-five thousand, four hundred five".