2121111755 has 24 divisors (see below), whose sum is σ = 2965317840. Its totient is φ = 1452306240.

The previous prime is 2121111689. The next prime is 2121111757. The reversal of 2121111755 is 5571111212.

It is a de Polignac number, because none of the positive numbers 2^k-2121111755 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2121111757) 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 23 ways as a sum of consecutive naturals, for example, 167600 + ... + 179810.

It is an arithmetic number, because the mean of its divisors is an integer number (123554910).

Almost surely, 2^2121111755 is an apocalyptic number.

2121111755 is a deficient number, since it is larger than the sum of its proper divisors (844206085).

2121111755 is a wasteful number, since it uses less digits than its factorization.

2121111755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12939 (or 12932 counting only the distinct ones).

The product of its digits is 700, while the sum is 26.

The square root of 2121111755 is about 46055.5290383250. The cubic root of 2121111755 is about 1284.8561775374.

Adding to 2121111755 its reverse (5571111212), we get a palindrome (7692222967).

The spelling of 2121111755 in words is "two billion, one hundred twenty-one million, one hundred eleven thousand, seven hundred fifty-five".