21423100129 has 2 divisors, whose sum is σ = 21423100130. Its totient is φ = 21423100128.

The previous prime is 21423100099. The next prime is 21423100169. The reversal of 21423100129 is 92100132412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18900750400 + 2522349729 = 137480^2 + 50223^2 .

It is a cyclic number.

It is not a de Polignac number, because 21423100129 - 2¹⁹ = 21422575841 is a prime.

It is not a weakly prime, because it can be changed into another prime (21423100169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711550064 + 10711550065.

It is an arithmetic number, because the mean of its divisors is an integer number (10711550065).

Almost surely, 2^21423100129 is an apocalyptic number.

It is an amenable number.

21423100129 is a deficient number, since it is larger than the sum of its proper divisors (1).

21423100129 is an equidigital number, since it uses as much as digits as its factorization.

21423100129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 25.

The spelling of 21423100129 in words is "twenty-one billion, four hundred twenty-three million, one hundred thousand, one hundred twenty-nine".