20101210121 has 2 divisors, whose sum is σ = 20101210122. Its totient is φ = 20101210120.

The previous prime is 20101210099. The next prime is 20101210127. The reversal of 20101210121 is 12101210102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15329163721 + 4772046400 = 123811^2 + 69080^2 .

It is a cyclic number.

It is not a de Polignac number, because 20101210121 - 2²⁶ = 20034101257 is a prime.

It is not a weakly prime, because it can be changed into another prime (20101210127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10050605060 + 10050605061.

It is an arithmetic number, because the mean of its divisors is an integer number (10050605061).

Almost surely, 2^20101210121 is an apocalyptic number.

It is an amenable number.

20101210121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20101210121 is an equidigital number, since it uses as much as digits as its factorization.

20101210121 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 11.

Adding to 20101210121 its reverse (12101210102), we get a palindrome (32202420223).

The spelling of 20101210121 in words is "twenty billion, one hundred one million, two hundred ten thousand, one hundred twenty-one".