21203332122121 has 8 divisors (see below), whose sum is σ = 22450808403720. Its totient is φ = 19955880446208.

The previous prime is 21203332122059. The next prime is 21203332122163. The reversal of 21203332122121 is 12122123330212.

It can be written as a sum of positive squares in 4 ways, for example, as 1190414105721 + 20012918016400 = 1091061^2 + 4473580^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21203332122121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21203332122821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4362406 + ... + 7838191.

It is an arithmetic number, because the mean of its divisors is an integer number (2806351050465).

Almost surely, 2^{21203332122121} is an apocalyptic number.

It is an amenable number.

21203332122121 is a deficient number, since it is larger than the sum of its proper divisors (1247476281599).

21203332122121 is a wasteful number, since it uses less digits than its factorization.

21203332122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12302843.

The product of its (nonzero) digits is 1728, while the sum is 25.

Adding to 21203332122121 its reverse (12122123330212), we get a palindrome (33325455452333).

The spelling of 21203332122121 in words is "twenty-one trillion, two hundred three billion, three hundred thirty-two million, one hundred twenty-two thousand, one hundred twenty-one".