21012112202121 has 6 divisors (see below), whose sum is σ = 30350828736410. Its totient is φ = 14008074801408.

The previous prime is 21012112202083. The next prime is 21012112202177. The reversal of 21012112202121 is 12120221121012.

21012112202121 is a `hidden beast` number, since 21 + 0 + 1 + 211 + 220 + 212 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19386946169721 + 1625166032400 = 4403061^2 + 1274820^2 .

It is not a de Polignac number, because 21012112202121 - 2¹³ = 21012112193929 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21012112202094 and 21012112202103.

It is not an unprimeable number, because it can be changed into a prime (21012112201121) 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 5 ways as a sum of consecutive naturals, for example, 1167339566776 + ... + 1167339566793.

Almost surely, 2^{21012112202121} is an apocalyptic number.

It is an amenable number.

21012112202121 is a deficient number, since it is larger than the sum of its proper divisors (9338716534289).

21012112202121 is a wasteful number, since it uses less digits than its factorization.

21012112202121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2334679133575 (or 2334679133572 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21012112202121 its reverse (12120221121012), we get a palindrome (33132333323133).

The spelling of 21012112202121 in words is "twenty-one trillion, twelve billion, one hundred twelve million, two hundred two thousand, one hundred twenty-one".