100012121221 has 2 divisors, whose sum is σ = 100012121222. Its totient is φ = 100012121220.

The previous prime is 100012121203. The next prime is 100012121257. The reversal of 100012121221 is 122121210001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76964630625 + 23047490596 = 277425^2 + 151814^2 .

It is a cyclic number.

It is not a de Polignac number, because 100012121221 - 2⁹ = 100012120709 is a prime.

It is a super-2 number, since 2×100012121221² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100012121821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50006060610 + 50006060611.

It is an arithmetic number, because the mean of its divisors is an integer number (50006060611).

Almost surely, 2^100012121221 is an apocalyptic number.

It is an amenable number.

100012121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

100012121221 is an equidigital number, since it uses as much as digits as its factorization.

100012121221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 100012121221 its reverse (122121210001), we get a palindrome (222133331222).

The spelling of 100012121221 in words is "one hundred billion, twelve million, one hundred twenty-one thousand, two hundred twenty-one".