21212010220201 has 4 divisors (see below), whose sum is σ = 21212019708100. Its totient is φ = 21212000732304.

The previous prime is 21212010220187. The next prime is 21212010220249. The reversal of 21212010220201 is 10202201021212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 9309510220201 + 11902500000000 = 3051149^2 + 3450000^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212010220201 - 2⁹ = 21212010219689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212010220301) 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, 666295 + ... + 6547363.

It is an arithmetic number, because the mean of its divisors is an integer number (5303004927025).

Almost surely, 2^{21212010220201} is an apocalyptic number.

It is an amenable number.

21212010220201 is a deficient number, since it is larger than the sum of its proper divisors (9487899).

21212010220201 is an equidigital number, since it uses as much as digits as its factorization.

21212010220201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9487898.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21212010220201 its reverse (10202201021212), we get a palindrome (31414211241413).

The spelling of 21212010220201 in words is "twenty-one trillion, two hundred twelve billion, ten million, two hundred twenty thousand, two hundred one".