210121212121 has 8 divisors (see below), whose sum is σ = 210699599360. Its totient is φ = 209543534928.

The previous prime is 210121212113. The next prime is 210121212149. The reversal of 210121212121 is 121212121012.

210121212121 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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 210121212121 - 2³ = 210121212113 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210121212095 and 210121212104.

It is not an unprimeable number, because it can be changed into a prime (210121212101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 417895 + ... + 771283.

It is an arithmetic number, because the mean of its divisors is an integer number (26337449920).

Almost surely, 2^210121212121 is an apocalyptic number.

It is an amenable number.

210121212121 is a deficient number, since it is larger than the sum of its proper divisors (578387239).

210121212121 is a wasteful number, since it uses less digits than its factorization.

210121212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355023.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 210121212121 its reverse (121212121012), we get a palindrome (331333333133).

The spelling of 210121212121 in words is "two hundred ten billion, one hundred twenty-one million, two hundred twelve thousand, one hundred twenty-one".