210210111112121 has 4 divisors (see below), whose sum is σ = 212138644241700. Its totient is φ = 208281577982544.

The previous prime is 210210111112117. The next prime is 210210111112139. The reversal of 210210111112121 is 121211111012012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 165207963555625 + 45002147556496 = 12853325^2 + 6708364^2 .

It is a cyclic number.

It is not a de Polignac number, because 210210111112121 - 2² = 210210111112117 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 210210111112121.

It is not an unprimeable number, because it can be changed into a prime (210210111112321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 964266564626 + ... + 964266564843.

It is an arithmetic number, because the mean of its divisors is an integer number (53034661060425).

Almost surely, 2^{210210111112121} is an apocalyptic number.

It is an amenable number.

210210111112121 is a deficient number, since it is larger than the sum of its proper divisors (1928533129579).

210210111112121 is a wasteful number, since it uses less digits than its factorization.

210210111112121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1928533129578.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 210210111112121 its reverse (121211111012012), we get a palindrome (331421222124133).

The spelling of 210210111112121 in words is "two hundred ten trillion, two hundred ten billion, one hundred eleven million, one hundred twelve thousand, one hundred twenty-one".