21135605633 has 4 divisors (see below), whose sum is σ = 21390251568. Its totient is φ = 20880959700.

The previous prime is 21135605629. The next prime is 21135605641. The reversal of 21135605633 is 33650653112.

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 21135605633 - 2² = 21135605629 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21135605593 and 21135605602.

It is not an unprimeable number, because it can be changed into a prime (21135602633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127322843 + ... + 127323008.

It is an arithmetic number, because the mean of its divisors is an integer number (5347562892).

Almost surely, 2^21135605633 is an apocalyptic number.

It is an amenable number.

21135605633 is a deficient number, since it is larger than the sum of its proper divisors (254645935).

21135605633 is an equidigital number, since it uses as much as digits as its factorization.

21135605633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254645934.

The product of its (nonzero) digits is 48600, while the sum is 35.

The spelling of 21135605633 in words is "twenty-one billion, one hundred thirty-five million, six hundred five thousand, six hundred thirty-three".