21201210212021 has 24 divisors (see below), whose sum is σ = 24811513062336. Its totient is φ = 18062774815680.

The previous prime is 21201210211999. The next prime is 21201210212057. The reversal of 21201210212021 is 12021201210212.

It is not a de Polignac number, because 21201210212021 - 2⁶ = 21201210211957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201210212621) 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 23 ways as a sum of consecutive naturals, for example, 213583961 + ... + 213683201.

It is an arithmetic number, because the mean of its divisors is an integer number (1033813044264).

Almost surely, 2^{21201210212021} is an apocalyptic number.

It is an amenable number.

21201210212021 is a deficient number, since it is larger than the sum of its proper divisors (3610302850315).

21201210212021 is a wasteful number, since it uses less digits than its factorization.

21201210212021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125529 (or 125522 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21201210212021 its reverse (12021201210212), we get a palindrome (33222411422233).

The spelling of 21201210212021 in words is "twenty-one trillion, two hundred one billion, two hundred ten million, two hundred twelve thousand, twenty-one".