11112121 has 8 divisors (see below), whose sum is σ = 11291400. Its totient is φ = 10934400.

The previous prime is 11112113. The next prime is 11112137. The reversal of 11112121 is 12121111.

It can be written as a sum of positive squares in 4 ways, for example, as 4247721 + 6864400 = 2061^2 + 2620^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 11112121 - 2³ = 11112113 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 11112098 and 11112107.

It is not an unprimeable number, because it can be changed into a prime (11112161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26965 + ... + 27373.

It is an arithmetic number, because the mean of its divisors is an integer number (1411425).

Almost surely, 2^11112121 is an apocalyptic number.

It is an amenable number.

11112121 is a deficient number, since it is larger than the sum of its proper divisors (179279).

11112121 is a wasteful number, since it uses less digits than its factorization.

11112121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 779.

The product of its digits is 4, while the sum is 10.

The square root of 11112121 is about 3333.4848132247. The cubic root of 11112121 is about 223.1510770182.

Adding to 11112121 its reverse (12121111), we get a palindrome (23233232).

It can be divided in two parts, 111 and 12121, that multiplied together give a palindrome (1345431).

The spelling of 11112121 in words is "eleven million, one hundred twelve thousand, one hundred twenty-one".