12212120021 has 4 divisors (see below), whose sum is σ = 12854863200. Its totient is φ = 11569376844.

The previous prime is 12212120003. The next prime is 12212120033. The reversal of 12212120021 is 12002121221.

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 12212120021 - 2⁶ = 12212119957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12212119978 and 12212120005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12212120071) 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, 321371561 + ... + 321371598.

It is an arithmetic number, because the mean of its divisors is an integer number (3213715800).

Almost surely, 2^12212120021 is an apocalyptic number.

It is an amenable number.

12212120021 is a deficient number, since it is larger than the sum of its proper divisors (642743179).

12212120021 is an equidigital number, since it uses as much as digits as its factorization.

12212120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642743178.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 12212120021 its reverse (12002121221), we get a palindrome (24214241242).

It can be divided in two parts, 122121200 and 21, that added together give a palindrome (122121221).

The spelling of 12212120021 in words is "twelve billion, two hundred twelve million, one hundred twenty thousand, twenty-one".