21379021633 has 4 divisors (see below), whose sum is σ = 21649642240. Its totient is φ = 21108401028.

The previous prime is 21379021621. The next prime is 21379021639. The reversal of 21379021633 is 33612097312.

It is a happy number.

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 21379021633 - 2²⁵ = 21345467201 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21379021592 and 21379021601.

It is not an unprimeable number, because it can be changed into a prime (21379021639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 135310185 + ... + 135310342.

It is an arithmetic number, because the mean of its divisors is an integer number (5412410560).

Almost surely, 2^21379021633 is an apocalyptic number.

It is an amenable number.

21379021633 is a deficient number, since it is larger than the sum of its proper divisors (270620607).

21379021633 is an equidigital number, since it uses as much as digits as its factorization.

21379021633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270620606.

The product of its (nonzero) digits is 40824, while the sum is 37.

The spelling of 21379021633 in words is "twenty-one billion, three hundred seventy-nine million, twenty-one thousand, six hundred thirty-three".