21120221212221 has 16 divisors (see below), whose sum is σ = 28171344668544. Its totient is φ = 14074623366144.

The previous prime is 21120221212217. The next prime is 21120221212249. The reversal of 21120221212221 is 12221212202112.

It is not a de Polignac number, because 21120221212221 - 2² = 21120221212217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120221212021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 122803936 + ... + 122975798.

It is an arithmetic number, because the mean of its divisors is an integer number (1760709041784).

Almost surely, 2^{21120221212221} is an apocalyptic number.

It is an amenable number.

21120221212221 is a deficient number, since it is larger than the sum of its proper divisors (7051123456323).

21120221212221 is a wasteful number, since it uses less digits than its factorization.

21120221212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187700.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 21120221212221 its reverse (12221212202112), we get a palindrome (33341433414333).

The spelling of 21120221212221 in words is "twenty-one trillion, one hundred twenty billion, two hundred twenty-one million, two hundred twelve thousand, two hundred twenty-one".