21221011221201 has 64 divisors (see below), whose sum is σ = 35530737868800. Its totient is φ = 12401406763200.

The previous prime is 21221011221161. The next prime is 21221011221217. The reversal of 21221011221201 is 10212211012212.

21221011221201 is a `hidden beast` number, since 21 + 2 + 210 + 11 + 221 + 201 = 666.

It is not a de Polignac number, because 21221011221201 - 2¹⁰ = 21221011220177 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221011221601) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1610091 + ... + 6710768.

It is an arithmetic number, because the mean of its divisors is an integer number (555167779200).

Almost surely, 2^{21221011221201} is an apocalyptic number.

It is an amenable number.

21221011221201 is a deficient number, since it is larger than the sum of its proper divisors (14309726647599).

21221011221201 is a wasteful number, since it uses less digits than its factorization.

21221011221201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8321187 (or 8321181 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21221011221201 its reverse (10212211012212), we get a palindrome (31433222233413).

It can be divided in two parts, 212210 and 11221201, that added together give a palindrome (11433411).

The spelling of 21221011221201 in words is "twenty-one trillion, two hundred twenty-one billion, eleven million, two hundred twenty-one thousand, two hundred one".