210021012121221 has 48 divisors (see below), whose sum is σ = 358659571196160. Its totient is φ = 115872693027840.

The previous prime is 210021012121189. The next prime is 210021012121243. The reversal of 210021012121221 is 122121210120012.

210021012121221 is a `hidden beast` number, since 2 + 100 + 210 + 12 + 121 + 221 = 666.

210021012121221 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 210021012121221 - 2⁵ = 210021012121189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 210021012121194 and 210021012121203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210021012121721) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 255352981 + ... + 256174133.

It is an arithmetic number, because the mean of its divisors is an integer number (7472074399920).

Almost surely, 2^{210021012121221} is an apocalyptic number.

210021012121221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

210021012121221 is a deficient number, since it is larger than the sum of its proper divisors (148638559074939).

210021012121221 is a wasteful number, since it uses less digits than its factorization.

210021012121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 961186 (or 961183 counting only the distinct ones).

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

Adding to 210021012121221 its reverse (122121210120012), we get a palindrome (332142222241233).

The spelling of 210021012121221 in words is "two hundred ten trillion, twenty-one billion, twelve million, one hundred twenty-one thousand, two hundred twenty-one".