21010100129 has 4 divisors (see below), whose sum is σ = 21457123584. Its totient is φ = 20563076676.

The previous prime is 21010100101. The next prime is 21010100179. The reversal of 21010100129 is 92100101012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21010100129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21010100179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 223511657 + ... + 223511750.

It is an arithmetic number, because the mean of its divisors is an integer number (5364280896).

Almost surely, 2^21010100129 is an apocalyptic number.

It is an amenable number.

21010100129 is a deficient number, since it is larger than the sum of its proper divisors (447023455).

21010100129 is an equidigital number, since it uses as much as digits as its factorization.

21010100129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 447023454.

The product of its (nonzero) digits is 36, while the sum is 17.

The spelling of 21010100129 in words is "twenty-one billion, ten million, one hundred thousand, one hundred twenty-nine".