21201022022101 has 4 divisors (see below), whose sum is σ = 21222033937900. Its totient is φ = 21180010106304.

The previous prime is 21201022022017. The next prime is 21201022022123. The reversal of 21201022022101 is 10122022010212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7739468360100 + 13461553662001 = 2781990^2 + 3668999^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201022022101 - 2⁹ = 21201022021589 is a prime.

It is a super-2 number, since 2×21201022022101² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201022022801) 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, 10505956386 + ... + 10505958403.

It is an arithmetic number, because the mean of its divisors is an integer number (5305508484475).

Almost surely, 2^{21201022022101} is an apocalyptic number.

It is an amenable number.

21201022022101 is a deficient number, since it is larger than the sum of its proper divisors (21011915799).

21201022022101 is a wasteful number, since it uses less digits than its factorization.

21201022022101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21011915798.

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

Adding to 21201022022101 its reverse (10122022010212), we get a palindrome (31323044032313).

The spelling of 21201022022101 in words is "twenty-one trillion, two hundred one billion, twenty-two million, twenty-two thousand, one hundred one".