220121211100001 has 4 divisors (see below), whose sum is σ = 221065937328132. Its totient is φ = 219176484871872.

The previous prime is 220121211099929. The next prime is 220121211100039. The reversal of 220121211100001 is 100001112121022.

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 58629878710225 + 161491332389776 = 7657015^2 + 12707924^2 .

It is a cyclic number.

It is not a de Polignac number, because 220121211100001 - 2⁴⁶ = 149752466922337 is a prime.

It is a super-2 number, since 2×220121211100001² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (220121211105001) 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, 472363113716 + ... + 472363114181.

It is an arithmetic number, because the mean of its divisors is an integer number (55266484332033).

Almost surely, 2^{220121211100001} is an apocalyptic number.

It is an amenable number.

220121211100001 is a deficient number, since it is larger than the sum of its proper divisors (944726228131).

220121211100001 is an equidigital number, since it uses as much as digits as its factorization.

220121211100001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 944726228130.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 220121211100001 its reverse (100001112121022), we get a palindrome (320122323221023).

The spelling of 220121211100001 in words is "two hundred twenty trillion, one hundred twenty-one billion, two hundred eleven million, one hundred thousand, one".