21220221211001 has 24 divisors (see below), whose sum is σ = 22295714805000. Its totient is φ = 20192762937600.

The previous prime is 21220221210967. The next prime is 21220221211043. The reversal of 21220221211001 is 10011212202212.

It can be written as a sum of positive squares in 4 ways, for example, as 1225059366976 + 19995161844025 = 1106824^2 + 4471595^2 .

It is not a de Polignac number, because 21220221211001 - 2²² = 21220217016697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21220221411001) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14795375 + ... + 16166123.

It is an arithmetic number, because the mean of its divisors is an integer number (928988116875).

Almost surely, 2^{21220221211001} is an apocalyptic number.

It is an amenable number.

21220221211001 is a deficient number, since it is larger than the sum of its proper divisors (1075493593999).

21220221211001 is a wasteful number, since it uses less digits than its factorization.

21220221211001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1371081 (or 1371050 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21220221211001 its reverse (10011212202212), we get a palindrome (31231433413213).

The spelling of 21220221211001 in words is "twenty-one trillion, two hundred twenty billion, two hundred twenty-one million, two hundred eleven thousand, one".