11011212121 has 32 divisors (see below), whose sum is σ = 14046068736. Its totient is φ = 8397000000.

The previous prime is 11011212097. The next prime is 11011212127. The reversal of 11011212121 is 12121211011.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 11011212121 - 2⁵ = 11011212089 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

11011212121 is a modest number, since divided by 212121 gives 11011 as remainder.

It is not an unprimeable number, because it can be changed into a prime (11011212127) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 700296 + ... + 715846.

It is an arithmetic number, because the mean of its divisors is an integer number (438939648).

Almost surely, 2^11011212121 is an apocalyptic number.

It is an amenable number.

11011212121 is a deficient number, since it is larger than the sum of its proper divisors (3034856615).

11011212121 is a wasteful number, since it uses less digits than its factorization.

11011212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15853.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 11011212121 its reverse (12121211011), we get a palindrome (23132423132).

The spelling of 11011212121 in words is "eleven billion, eleven million, two hundred twelve thousand, one hundred twenty-one".