12122120021 has 4 divisors (see below), whose sum is σ = 13224130944.
Its totient is φ = 11020109100.
The previous prime is 12122119951. The next prime is 12122120033. The reversal of 12122120021 is 12002122121.
Adding to 12122120021 its reverse (12002122121), we get a palindrome (24124242142).
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, and also an emirpimes, since its reverse is a distinct semiprime: 12002122121 = 11 ⋅1091102011.
It is not a de Polignac number, because 12122120021 - 222 = 12117925717 is a prime.
It is a Duffinian number.
It is a junction number, because it is equal to n+sod(n) for n = 12122119978 and 12122120005.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (12122120051) 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, 551005445 + ... + 551005466.
It is an arithmetic number, because the mean of its divisors is an integer number (3306032736).
Almost surely, 212122120021 is an apocalyptic number.
12122120021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.
It is an amenable number.
12122120021 is a deficient number, since it is larger than the sum of its proper divisors (1102010923).
12122120021 is a wasteful number, since it uses less digits than its factorization.
12122120021 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1102010922.
The product of its (nonzero) digits is 32, while the sum is 14.
The spelling of 12122120021 in words is "twelve billion, one hundred twenty-two million, one hundred twenty thousand, twenty-one".