20121212120021 has 4 divisors (see below), whose sum is σ = 20121336850272. Its totient is φ = 20121087389772.

The previous prime is 20121212120017. The next prime is 20121212120027. The reversal of 20121212120021 is 12002121212102.

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 20121212120021 - 2² = 20121212120017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121212120027) 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, 62122835 + ... + 62445888.

It is an arithmetic number, because the mean of its divisors is an integer number (5030334212568).

Almost surely, 2^{20121212120021} is an apocalyptic number.

It is an amenable number.

20121212120021 is a deficient number, since it is larger than the sum of its proper divisors (124730251).

20121212120021 is a wasteful number, since it uses less digits than its factorization.

20121212120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124730250.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 20121212120021 its reverse (12002121212102), we get a palindrome (32123333332123).

The spelling of 20121212120021 in words is "twenty trillion, one hundred twenty-one billion, two hundred twelve million, one hundred twenty thousand, twenty-one".