21211222120201 has 8 divisors (see below), whose sum is σ = 21685193034120. Its totient is φ = 20739983027712.

The previous prime is 21211222120163. The next prime is 21211222120211. The reversal of 21211222120201 is 10202122211212.

It can be written as a sum of positive squares in 4 ways, for example, as 11291777384976 + 9919444735225 = 3360324^2 + 3149515^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21211222120201 - 2³⁷ = 21073783166729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211222120211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 682939656 + ... + 682970713.

It is an arithmetic number, because the mean of its divisors is an integer number (2710649129265).

Almost surely, 2^{21211222120201} is an apocalyptic number.

It is an amenable number.

21211222120201 is a deficient number, since it is larger than the sum of its proper divisors (473970913919).

21211222120201 is a wasteful number, since it uses less digits than its factorization.

21211222120201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1365910715.

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

Adding to 21211222120201 its reverse (10202122211212), we get a palindrome (31413344331413).

The spelling of 21211222120201 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-two million, one hundred twenty thousand, two hundred one".