10011111222121 has 4 divisors (see below), whose sum is σ = 10011279194244. Its totient is φ = 10010943250000.

The previous prime is 10011111222023. The next prime is 10011111222143. The reversal of 10011111222121 is 12122211111001.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7274138037721 + 2736973184400 = 2697061^2 + 1654380^2 .

It is a cyclic number.

It is not a de Polignac number, because 10011111222121 - 2¹¹ = 10011111220073 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10011111222095 and 10011111222104.

It is not an unprimeable number, because it can be changed into a prime (10011111222221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83896630 + ... + 84015871.

It is an arithmetic number, because the mean of its divisors is an integer number (2502819798561).

Almost surely, 2^{10011111222121} is an apocalyptic number.

It is an amenable number.

10011111222121 is a deficient number, since it is larger than the sum of its proper divisors (167972123).

10011111222121 is an equidigital number, since it uses as much as digits as its factorization.

10011111222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167972122.

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

Adding to 10011111222121 its reverse (12122211111001), we get a palindrome (22133322333122).

The spelling of 10011111222121 in words is "ten trillion, eleven billion, one hundred eleven million, two hundred twenty-two thousand, one hundred twenty-one".