21201222220001 has 6 divisors (see below), whose sum is σ = 21472989215202. Its totient is φ = 20932852312320.

The previous prime is 21201222219941. The next prime is 21201222220141. The reversal of 21201222220001 is 10002222210212.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 15180382232401 + 6020839987600 = 3896201^2 + 2453740^2 .

It is not a de Polignac number, because 21201222220001 - 2¹⁴ = 21201222203617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21201222220301) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1698537440 + ... + 1698549921.

It is an arithmetic number, because the mean of its divisors is an integer number (3578831535867).

Almost surely, 2^{21201222220001} is an apocalyptic number.

It is an amenable number.

21201222220001 is a deficient number, since it is larger than the sum of its proper divisors (271766995201).

21201222220001 is an frugal number, since it uses more digits than its factorization.

21201222220001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3397087519 (or 3397087440 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21201222220001 its reverse (10002222210212), we get a palindrome (31203444430213).

The spelling of 21201222220001 in words is "twenty-one trillion, two hundred one billion, two hundred twenty-two million, two hundred twenty thousand, one".