21131211210121 has 8 divisors (see below), whose sum is σ = 22376574118080. Its totient is φ = 19899167691888.

The previous prime is 21131211210113. The next prime is 21131211210133. The reversal of 21131211210121 is 12101211213112.

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

It is a cyclic number.

It is not a de Polignac number, because 21131211210121 - 2³ = 21131211210113 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21131211210101) 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, 3329844166 + ... + 3329850511.

It is an arithmetic number, because the mean of its divisors is an integer number (2797071764760).

Almost surely, 2^{21131211210121} is an apocalyptic number.

It is an amenable number.

21131211210121 is a deficient number, since it is larger than the sum of its proper divisors (1245362907959).

21131211210121 is a wasteful number, since it uses less digits than its factorization.

21131211210121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6659694863.

The product of its (nonzero) digits is 48, while the sum is 19.

Adding to 21131211210121 its reverse (12101211213112), we get a palindrome (33232422423233).

The spelling of 21131211210121 in words is "twenty-one trillion, one hundred thirty-one billion, two hundred eleven million, two hundred ten thousand, one hundred twenty-one".