21012121222201 has 4 divisors (see below), whose sum is σ = 21459187631232. Its totient is φ = 20565054813172.

The previous prime is 21012121222199. The next prime is 21012121222249. The reversal of 21012121222201 is 10222212121012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21012121222201 - 2¹ = 21012121222199 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012121222271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 223533204445 + ... + 223533204538.

It is an arithmetic number, because the mean of its divisors is an integer number (5364796907808).

Almost surely, 2^{21012121222201} is an apocalyptic number.

It is an amenable number.

21012121222201 is a deficient number, since it is larger than the sum of its proper divisors (447066409031).

21012121222201 is an equidigital number, since it uses as much as digits as its factorization.

21012121222201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 447066409030.

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

Adding to 21012121222201 its reverse (10222212121012), we get a palindrome (31234333343213).

The spelling of 21012121222201 in words is "twenty-one trillion, twelve billion, one hundred twenty-one million, two hundred twenty-two thousand, two hundred one".