11201212121 has 12 divisors (see below), whose sum is σ = 12485495232. Its totient is φ = 10039491000.

The previous prime is 11201212117. The next prime is 11201212171. The reversal of 11201212121 is 12121210211.

It is not a de Polignac number, because 11201212121 - 2² = 11201212117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 11201212096 and 11201212105.

It is not an unprimeable number, because it can be changed into a prime (11201212111) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 643325 + ... + 660506.

It is an arithmetic number, because the mean of its divisors is an integer number (1040457936).

Almost surely, 2^11201212121 is an apocalyptic number.

11201212121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11201212121 is a deficient number, since it is larger than the sum of its proper divisors (1284283111).

11201212121 is a wasteful number, since it uses less digits than its factorization.

11201212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1303924 (or 1303913 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 11201212121 its reverse (12121210211), we get a palindrome (23322422332).

It can be divided in two parts, 11201 and 212121, that added together give a palindrome (223322).

The spelling of 11201212121 in words is "eleven billion, two hundred one million, two hundred twelve thousand, one hundred twenty-one".