21211010129 has 2 divisors, whose sum is σ = 21211010130. Its totient is φ = 21211010128.

The previous prime is 21211010099. The next prime is 21211010131. The reversal of 21211010129 is 92101011212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21211009600 + 529 = 145640^2 + 23^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21211010129 is a prime.

Together with 21211010131, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21211010129.

It is not a weakly prime, because it can be changed into another prime (21211010189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605505064 + 10605505065.

It is an arithmetic number, because the mean of its divisors is an integer number (10605505065).

Almost surely, 2^21211010129 is an apocalyptic number.

It is an amenable number.

21211010129 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211010129 is an equidigital number, since it uses as much as digits as its factorization.

21211010129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 20.

The spelling of 21211010129 in words is "twenty-one billion, two hundred eleven million, ten thousand, one hundred twenty-nine".