21012212110221 has 24 divisors (see below), whose sum is σ = 30625019006400. Its totient is φ = 13882219560000.

The previous prime is 21012212110199. The next prime is 21012212110223. The reversal of 21012212110221 is 12201121221012.

21012212110221 is a `hidden beast` number, since 2 + 10 + 1 + 221 + 211 + 0 + 221 = 666.

It is not a de Polignac number, because 21012212110221 - 2²⁹ = 21011675239309 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21012212110194 and 21012212110203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012212110223) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22921200 + ... + 23820281.

It is an arithmetic number, because the mean of its divisors is an integer number (1276042458600).

Almost surely, 2^{21012212110221} is an apocalyptic number.

It is an amenable number.

21012212110221 is a deficient number, since it is larger than the sum of its proper divisors (9612806896179).

21012212110221 is a wasteful number, since it uses less digits than its factorization.

21012212110221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46741937 (or 46741934 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21012212110221 its reverse (12201121221012), we get a palindrome (33213333331233).

The spelling of 21012212110221 in words is "twenty-one trillion, twelve billion, two hundred twelve million, one hundred ten thousand, two hundred twenty-one".