21022002121221 has 96 divisors (see below), whose sum is σ = 32651818647552. Its totient is φ = 13003064680320.

The previous prime is 21022002121213. The next prime is 21022002121273. The reversal of 21022002121221 is 12212120022012.

It is a happy number.

21022002121221 is a `hidden beast` number, since 2 + 10 + 220 + 0 + 212 + 1 + 221 = 666.

It is not a de Polignac number, because 21022002121221 - 2³ = 21022002121213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21022002121194 and 21022002121203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022002125221) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 341529370 + ... + 341590916.

It is an arithmetic number, because the mean of its divisors is an integer number (340123110912).

Almost surely, 2^{21022002121221} is an apocalyptic number.

It is an amenable number.

21022002121221 is a deficient number, since it is larger than the sum of its proper divisors (11629816526331).

21022002121221 is a wasteful number, since it uses less digits than its factorization.

21022002121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61983 (or 61980 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21022002121221 its reverse (12212120022012), we get a palindrome (33234122143233).

The spelling of 21022002121221 in words is "twenty-one trillion, twenty-two billion, two million, one hundred twenty-one thousand, two hundred twenty-one".