20101121212121 has 4 divisors (see below), whose sum is σ = 20101336477200. Its totient is φ = 20100905947044.

The previous prime is 20101121212111. The next prime is 20101121212129. The reversal of 20101121212121 is 12121212110102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20101121212121 - 2¹⁸ = 20101120949977 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 20101121212121.

It is not an unprimeable number, because it can be changed into a prime (20101121212129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107492411 + ... + 107679248.

It is an arithmetic number, because the mean of its divisors is an integer number (5025334119300).

Almost surely, 2^{20101121212121} is an apocalyptic number.

It is an amenable number.

20101121212121 is a deficient number, since it is larger than the sum of its proper divisors (215265079).

20101121212121 is an equidigital number, since it uses as much as digits as its factorization.

20101121212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215265078.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 20101121212121 its reverse (12121212110102), we get a palindrome (32222333322223).

The spelling of 20101121212121 in words is "twenty trillion, one hundred one billion, one hundred twenty-one million, two hundred twelve thousand, one hundred twenty-one".