21221012021201 has 4 divisors (see below), whose sum is σ = 21221178688512. Its totient is φ = 21220845353892.

The previous prime is 21221012021159. The next prime is 21221012021233. The reversal of 21221012021201 is 10212021012212.

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 a cyclic number.

It is not a de Polignac number, because 21221012021201 - 2¹⁴ = 21221012004817 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21221012021201.

It is not an unprimeable number, because it can be changed into a prime (21221012081201) 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, 83142521 + ... + 83397366.

It is an arithmetic number, because the mean of its divisors is an integer number (5305294672128).

Almost surely, 2^{21221012021201} is an apocalyptic number.

It is an amenable number.

21221012021201 is a deficient number, since it is larger than the sum of its proper divisors (166667311).

21221012021201 is a wasteful number, since it uses less digits than its factorization.

21221012021201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166667310.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21221012021201 its reverse (10212021012212), we get a palindrome (31433033033413).

The spelling of 21221012021201 in words is "twenty-one trillion, two hundred twenty-one billion, twelve million, twenty-one thousand, two hundred one".