2102121210021 has 16 divisors (see below), whose sum is σ = 3203416960128. Its totient is φ = 1201142880000.

The previous prime is 2102121210017. The next prime is 2102121210029. The reversal of 2102121210021 is 1200121212012.

It is not a de Polignac number, because 2102121210021 - 2² = 2102121210017 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2102121210029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2510880 + ... + 3241721.

It is an arithmetic number, because the mean of its divisors is an integer number (200213560008).

Almost surely, 2^{2102121210021} is an apocalyptic number.

2102121210021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2102121210021 is a deficient number, since it is larger than the sum of its proper divisors (1101295750107).

2102121210021 is a wasteful number, since it uses less digits than its factorization.

2102121210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5770012.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 2102121210021 its reverse (1200121212012), we get a palindrome (3302242422033).

The spelling of 2102121210021 in words is "two trillion, one hundred two billion, one hundred twenty-one million, two hundred ten thousand, twenty-one".