100231221221 has 4 divisors (see below), whose sum is σ = 100232214732. Its totient is φ = 100230227712.

The previous prime is 100231221187. The next prime is 100231221239. The reversal of 100231221221 is 122122132001.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 40044412321 + 60186808900 = 200111^2 + 245330^2 .

It is a cyclic number.

It is not a de Polignac number, because 100231221221 - 2⁶ = 100231221157 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 100231221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100231221241) 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, 325820 + ... + 553733.

It is an arithmetic number, because the mean of its divisors is an integer number (25058053683).

Almost surely, 2^100231221221 is an apocalyptic number.

It is an amenable number.

100231221221 is a deficient number, since it is larger than the sum of its proper divisors (993511).

100231221221 is an equidigital number, since it uses as much as digits as its factorization.

100231221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 993510.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 100231221221 its reverse (122122132001), we get a palindrome (222353353222).

The spelling of 100231221221 in words is "one hundred billion, two hundred thirty-one million, two hundred twenty-one thousand, two hundred twenty-one".