100212121 has 2 divisors, whose sum is σ = 100212122. Its totient is φ = 100212120.

The previous prime is 100212113. The next prime is 100212143. The reversal of 100212121 is 121212001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76825225 + 23386896 = 8765^2 + 4836^2 .

It is a cyclic number.

It is not a de Polignac number, because 100212121 - 2³ = 100212113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 100212098 and 100212107.

It is not a weakly prime, because it can be changed into another prime (100212421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50106060 + 50106061.

It is an arithmetic number, because the mean of its divisors is an integer number (50106061).

Almost surely, 2^100212121 is an apocalyptic number.

It is an amenable number.

100212121 is a deficient number, since it is larger than the sum of its proper divisors (1).

100212121 is an equidigital number, since it uses as much as digits as its factorization.

100212121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 100212121 is about 10010.6004315426. The cubic root of 100212121 is about 464.4868444007.

Adding to 100212121 its reverse (121212001), we get a palindrome (221424122).

The spelling of 100212121 in words is "one hundred million, two hundred twelve thousand, one hundred twenty-one".