21202011210021 has 4 divisors (see below), whose sum is σ = 28269348280032. Its totient is φ = 14134674140012.

The previous prime is 21202011210013. The next prime is 21202011210209. The reversal of 21202011210021 is 12001211020212.

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 21202011210021 - 2³ = 21202011210013 is a prime.

It is a super-2 number, since 2×21202011210021² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202011211021) 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, 3533668535001 + ... + 3533668535006.

It is an arithmetic number, because the mean of its divisors is an integer number (7067337070008).

Almost surely, 2^{21202011210021} is an apocalyptic number.

It is an amenable number.

21202011210021 is a deficient number, since it is larger than the sum of its proper divisors (7067337070011).

21202011210021 is an equidigital number, since it uses as much as digits as its factorization.

21202011210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7067337070010.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21202011210021 its reverse (12001211020212), we get a palindrome (33203222230233).

The spelling of 21202011210021 in words is "twenty-one trillion, two hundred two billion, eleven million, two hundred ten thousand, twenty-one".