2121212210021 has 12 divisors (see below), whose sum is σ = 2218287866592. Its totient is φ = 2028217730616.

The previous prime is 2121212210017. The next prime is 2121212210027. The reversal of 2121212210021 is 1200122121212.

It is not a de Polignac number, because 2121212210021 - 2² = 2121212210017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121212210027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 642830 + ... + 2157696.

It is an arithmetic number, because the mean of its divisors is an integer number (184857322216).

Almost surely, 2^{2121212210021} is an apocalyptic number.

It is an amenable number.

2121212210021 is a deficient number, since it is larger than the sum of its proper divisors (97075656571).

2121212210021 is a wasteful number, since it uses less digits than its factorization.

2121212210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1517560 (or 1517537 counting only the distinct ones).

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

Adding to 2121212210021 its reverse (1200122121212), we get a palindrome (3321334331233).

The spelling of 2121212210021 in words is "two trillion, one hundred twenty-one billion, two hundred twelve million, two hundred ten thousand, twenty-one".