11212121220021 has 24 divisors (see below), whose sum is σ = 17048648560320. Its totient is φ = 7080933110976.

The previous prime is 11212121219941. The next prime is 11212121220023. The reversal of 11212121220021 is 12002212121211.

11212121220021 is a `hidden beast` number, since 112 + 121 + 212 + 200 + 21 = 666.

It is not a de Polignac number, because 11212121220021 - 2²⁵ = 11212087665589 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11212121219976 and 11212121220003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11212121220023) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1118296 + ... + 4865678.

It is an arithmetic number, because the mean of its divisors is an integer number (710360356680).

Almost surely, 2^{11212121220021} is an apocalyptic number.

It is an amenable number.

11212121220021 is a deficient number, since it is larger than the sum of its proper divisors (5836527340299).

11212121220021 is a wasteful number, since it uses less digits than its factorization.

11212121220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3764905 (or 3764902 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 11212121220021 its reverse (12002212121211), we get a palindrome (23214333341232).

The spelling of 11212121220021 in words is "eleven trillion, two hundred twelve billion, one hundred twenty-one million, two hundred twenty thousand, twenty-one".