21202122210121 has 16 divisors (see below), whose sum is σ = 21658104482560. Its totient is φ = 20751569055360.

The previous prime is 21202122210083. The next prime is 21202122210131. The reversal of 21202122210121 is 12101222120212.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21202122210121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21202122210131) 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, 2106946 + ... + 6844228.

It is an arithmetic number, because the mean of its divisors is an integer number (1353631530160).

Almost surely, 2^{21202122210121} is an apocalyptic number.

It is an amenable number.

21202122210121 is a deficient number, since it is larger than the sum of its proper divisors (455982272439).

21202122210121 is a wasteful number, since it uses less digits than its factorization.

21202122210121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4737856.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21202122210121 its reverse (12101222120212), we get a palindrome (33303344330333).

The spelling of 21202122210121 in words is "twenty-one trillion, two hundred two billion, one hundred twenty-two million, two hundred ten thousand, one hundred twenty-one".