221020012221221 has 4 divisors (see below), whose sum is σ = 221021452141344. Its totient is φ = 221018572301100.

The previous prime is 221020012221209. The next prime is 221020012221317. The reversal of 221020012221221 is 122122210020122.

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 221020012221221 - 2⁶ = 221020012221157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221020012221193 and 221020012221202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221020012223221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 719729795 + ... + 720036816.

It is an arithmetic number, because the mean of its divisors is an integer number (55255363035336).

Almost surely, 2^{221020012221221} is an apocalyptic number.

It is an amenable number.

221020012221221 is a deficient number, since it is larger than the sum of its proper divisors (1439920123).

221020012221221 is a wasteful number, since it uses less digits than its factorization.

221020012221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1439920122.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 221020012221221 its reverse (122122210020122), we get a palindrome (343142222241343).

The spelling of 221020012221221 in words is "two hundred twenty-one trillion, twenty billion, twelve million, two hundred twenty-one thousand, two hundred twenty-one".