11212112121 has 16 divisors (see below), whose sum is σ = 17319168384. Its totient is φ = 6319154304.

The previous prime is 11212112101. The next prime is 11212112143. The reversal of 11212112121 is 12121121211.

It is a happy number.

It is not a de Polignac number, because 11212112121 - 2²¹ = 11210014969 is a prime.

It is a super-2 number, since 2×11212112121² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 11212112121.

It is not an unprimeable number, because it can be changed into a prime (11212112101) 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, 3655386 + ... + 3658451.

It is an arithmetic number, because the mean of its divisors is an integer number (1082448024).

Almost surely, 2^11212112121 is an apocalyptic number.

It is an amenable number.

11212112121 is a deficient number, since it is larger than the sum of its proper divisors (6107056263).

11212112121 is an equidigital number, since it uses as much as digits as its factorization.

11212112121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7313920.

The product of its digits is 16, while the sum is 15.

Adding to 11212112121 its reverse (12121121211), we get a palindrome (23333233332).

The spelling of 11212112121 in words is "eleven billion, two hundred twelve million, one hundred twelve thousand, one hundred twenty-one".