21001111222129 has 2 divisors, whose sum is σ = 21001111222130. Its totient is φ = 21001111222128.

The previous prime is 21001111222109. The next prime is 21001111222199. The reversal of 21001111222129 is 92122211110012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16547525658225 + 4453585563904 = 4067865^2 + 2110352^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001111222129 - 2⁷ = 21001111222001 is a prime.

It is a super-3 number, since 3×21001111222129³ (a number of 41 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21001111222109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500555611064 + 10500555611065.

It is an arithmetic number, because the mean of its divisors is an integer number (10500555611065).

Almost surely, 2^{21001111222129} is an apocalyptic number.

It is an amenable number.

21001111222129 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001111222129 is an equidigital number, since it uses as much as digits as its factorization.

21001111222129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 25.

The spelling of 21001111222129 in words is "twenty-one trillion, one billion, one hundred eleven million, two hundred twenty-two thousand, one hundred twenty-nine".