21110000012221 has 4 divisors (see below), whose sum is σ = 21131740486944. Its totient is φ = 21088259537500.

The previous prime is 21110000012209. The next prime is 21110000012267. The reversal of 21110000012221 is 12221000001112.

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 21110000012221 - 2¹⁹ = 21109999487933 is a prime.

It is a super-4 number, since 4×21110000012221⁴ (a number of 54 digits) contains 4444 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 (21110000082221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10870235905 + ... + 10870237846.

It is an arithmetic number, because the mean of its divisors is an integer number (5282935121736).

Almost surely, 2^{21110000012221} is an apocalyptic number.

It is an amenable number.

21110000012221 is a deficient number, since it is larger than the sum of its proper divisors (21740474723).

21110000012221 is an equidigital number, since it uses as much as digits as its factorization.

21110000012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21740474722.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21110000012221 its reverse (12221000001112), we get a palindrome (33331000013333).

The spelling of 21110000012221 in words is "twenty-one trillion, one hundred ten billion, twelve thousand, two hundred twenty-one".