20121233111 has 16 divisors (see below), whose sum is σ = 24225154560. Its totient is φ = 16326113760.

The previous prime is 20121233101. The next prime is 20121233137. The reversal of 20121233111 is 11133212102.

It is a cyclic number.

It is not a de Polignac number, because 20121233111 - 2⁶ = 20121233047 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 20121233111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121233101) 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, 110606 + ... + 229076.

It is an arithmetic number, because the mean of its divisors is an integer number (1514072160).

Almost surely, 2^20121233111 is an apocalyptic number.

20121233111 is a deficient number, since it is larger than the sum of its proper divisors (4103921449).

20121233111 is a wasteful number, since it uses less digits than its factorization.

20121233111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119774.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 20121233111 its reverse (11133212102), we get a palindrome (31254445213).

The spelling of 20121233111 in words is "twenty billion, one hundred twenty-one million, two hundred thirty-three thousand, one hundred eleven".