21212122122201 has 4 divisors (see below), whose sum is σ = 28282829496272. Its totient is φ = 14141414748132.

The previous prime is 21212122122193. The next prime is 21212122122251. The reversal of 21212122122201 is 10222122121212.

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 not a de Polignac number, because 21212122122201 - 2³ = 21212122122193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212122122251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3535353687031 + ... + 3535353687036.

It is an arithmetic number, because the mean of its divisors is an integer number (7070707374068).

Almost surely, 2^{21212122122201} is an apocalyptic number.

It is an amenable number.

21212122122201 is a deficient number, since it is larger than the sum of its proper divisors (7070707374071).

21212122122201 is an equidigital number, since it uses as much as digits as its factorization.

21212122122201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7070707374070.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 21212122122201 its reverse (10222122121212), we get a palindrome (31434244243413).

The spelling of 21212122122201 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty-two million, one hundred twenty-two thousand, two hundred one".