21202133021 has 4 divisors (see below), whose sum is σ = 21218557344. Its totient is φ = 21185708700.

The previous prime is 21202132979. The next prime is 21202133039. The reversal of 21202133021 is 12033120212.

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 a de Polignac number, because none of the positive numbers 2^k-21202133021 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 (21202133081) 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, 8210225 + ... + 8212806.

It is an arithmetic number, because the mean of its divisors is an integer number (5304639336).

Almost surely, 2^21202133021 is an apocalyptic number.

It is an amenable number.

21202133021 is a deficient number, since it is larger than the sum of its proper divisors (16424323).

21202133021 is a wasteful number, since it uses less digits than its factorization.

21202133021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16424322.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21202133021 its reverse (12033120212), we get a palindrome (33235253233).

The spelling of 21202133021 in words is "twenty-one billion, two hundred two million, one hundred thirty-three thousand, twenty-one".