11212120021 has 4 divisors (see below), whose sum is σ = 11573801344. Its totient is φ = 10850438700.

The previous prime is 11212119979. The next prime is 11212120033. The reversal of 11212120021 is 12002121211.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11212120021 - 2²¹ = 11210022869 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11212119983 and 11212120010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11212120081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 180840615 + ... + 180840676.

It is an arithmetic number, because the mean of its divisors is an integer number (2893450336).

Almost surely, 2^11212120021 is an apocalyptic number.

It is an amenable number.

11212120021 is a deficient number, since it is larger than the sum of its proper divisors (361681323).

11212120021 is an equidigital number, since it uses as much as digits as its factorization.

11212120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361681322.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 11212120021 its reverse (12002121211), we get a palindrome (23214241232).

The spelling of 11212120021 in words is "eleven billion, two hundred twelve million, one hundred twenty thousand, twenty-one".