20111110212121 has 16 divisors (see below), whose sum is σ = 20242928369664. Its totient is φ = 19979701807824.

The previous prime is 20111110212077. The next prime is 20111110212133. The reversal of 20111110212121 is 12121201111102.

It is a cyclic number.

It is not a de Polignac number, because 20111110212121 - 2¹⁹ = 20111109687833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20111110212095 and 20111110212104.

It is not an unprimeable number, because it can be changed into a prime (20111110212161) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 241032216 + ... + 241115638.

It is an arithmetic number, because the mean of its divisors is an integer number (1265183023104).

Almost surely, 2^{20111110212121} is an apocalyptic number.

It is an amenable number.

20111110212121 is a deficient number, since it is larger than the sum of its proper divisors (131818157543).

20111110212121 is a wasteful number, since it uses less digits than its factorization.

20111110212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85860.

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

Adding to 20111110212121 its reverse (12121201111102), we get a palindrome (32232311323223).

It can be divided in two parts, 201111102 and 12121, that multiplied together give a palindrome (2437667667342).

The spelling of 20111110212121 in words is "twenty trillion, one hundred eleven billion, one hundred ten million, two hundred twelve thousand, one hundred twenty-one".