21133621633 has 4 divisors (see below), whose sum is σ = 21327508180. Its totient is φ = 20939735088.

The previous prime is 21133621627. The next prime is 21133621637. The reversal of 21133621633 is 33612633112.

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 7372454769 + 13761166864 = 85863^2 + 117308^2 .

It is a cyclic number.

It is not a de Polignac number, because 21133621633 - 2¹⁷ = 21133490561 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21133621595 and 21133621604.

It is not an unprimeable number, because it can be changed into a prime (21133621637) 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, 96943110 + ... + 96943327.

It is an arithmetic number, because the mean of its divisors is an integer number (5331877045).

Almost surely, 2^21133621633 is an apocalyptic number.

It is an amenable number.

21133621633 is a deficient number, since it is larger than the sum of its proper divisors (193886547).

21133621633 is a wasteful number, since it uses less digits than its factorization.

21133621633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193886546.

The product of its digits is 11664, while the sum is 31.

The spelling of 21133621633 in words is "twenty-one billion, one hundred thirty-three million, six hundred twenty-one thousand, six hundred thirty-three".