21210120111021 has 8 divisors (see below), whose sum is σ = 28380090043680. Its totient is φ = 14090115126192.

The previous prime is 21210120111013. The next prime is 21210120111079. The reversal of 21210120111021 is 12011102101212.

It is a happy number.

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

It is not a de Polignac number, because 21210120111021 - 2³ = 21210120111013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210120111001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12491235966 + ... + 12491237663.

It is an arithmetic number, because the mean of its divisors is an integer number (3547511255460).

Almost surely, 2^{21210120111021} is an apocalyptic number.

It is an amenable number.

21210120111021 is a deficient number, since it is larger than the sum of its proper divisors (7169969932659).

21210120111021 is a wasteful number, since it uses less digits than its factorization.

21210120111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24982473915.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21210120111021 its reverse (12011102101212), we get a palindrome (33221222212233).

The spelling of 21210120111021 in words is "twenty-one trillion, two hundred ten billion, one hundred twenty million, one hundred eleven thousand, twenty-one".