21221222021101 has 4 divisors (see below), whose sum is σ = 21221249558652. Its totient is φ = 21221194483552.

The previous prime is 21221222021057. The next prime is 21221222021119. The reversal of 21221222021101 is 10112022212212.

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 17206949311876 + 4014272709225 = 4148126^2 + 2003565^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221222021101 - 2¹⁵ = 21221221988333 is a prime.

It is a super-2 number, since 2×21221222021101² (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 (21221222051101) 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, 12578536 + ... + 14165521.

It is an arithmetic number, because the mean of its divisors is an integer number (5305312389663).

Almost surely, 2^{21221222021101} is an apocalyptic number.

It is an amenable number.

21221222021101 is a deficient number, since it is larger than the sum of its proper divisors (27537551).

21221222021101 is an equidigital number, since it uses as much as digits as its factorization.

21221222021101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27537550.

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

Adding to 21221222021101 its reverse (10112022212212), we get a palindrome (31333244233313).

The spelling of 21221222021101 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twenty-two million, twenty-one thousand, one hundred one".