21221002012021 has 8 divisors (see below), whose sum is σ = 24253943529920. Its totient is φ = 18188402944608.

The previous prime is 21221002012009. The next prime is 21221002012033. The reversal of 21221002012021 is 12021020012212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21221002012009) and next prime (21221002012033).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21221002012021 - 2⁷ = 21221002011893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21221002011986 and 21221002012004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221002016021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85479816 + ... + 85727713.

It is an arithmetic number, because the mean of its divisors is an integer number (3031742941240).

Almost surely, 2^{21221002012021} is an apocalyptic number.

It is an amenable number.

21221002012021 is a deficient number, since it is larger than the sum of its proper divisors (3032941517899).

21221002012021 is a wasteful number, since it uses less digits than its factorization.

21221002012021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171225243.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21221002012021 its reverse (12021020012212), we get a palindrome (33242022024233).

The spelling of 21221002012021 in words is "twenty-one trillion, two hundred twenty-one billion, two million, twelve thousand, twenty-one".