210121110212121 has 12 divisors (see below), whose sum is σ = 303720662396580. Its totient is φ = 139982713022880.

The previous prime is 210121110212071. The next prime is 210121110212173. The reversal of 210121110212121 is 121212011121012.

It is a happy number.

210121110212121 is a `hidden beast` number, since 210 + 1 + 211 + 10 + 21 + 212 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 79106989312521 + 131014120899600 = 8894211^2 + 11446140^2 .

It is not a de Polignac number, because 210121110212121 - 2¹¹ = 210121110210073 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 210121110212094 and 210121110212103.

It is not an unprimeable number, because it can be changed into a prime (210121110212021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8168912970 + ... + 8168938691.

It is an arithmetic number, because the mean of its divisors is an integer number (25310055199715).

Almost surely, 2^{210121110212121} is an apocalyptic number.

It is an amenable number.

210121110212121 is a deficient number, since it is larger than the sum of its proper divisors (93599552184459).

210121110212121 is a wasteful number, since it uses less digits than its factorization.

210121110212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16337853096 (or 16337853093 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 210121110212121 its reverse (121212011121012), we get a palindrome (331333121333133).

The spelling of 210121110212121 in words is "two hundred ten trillion, one hundred twenty-one billion, one hundred ten million, two hundred twelve thousand, one hundred twenty-one".