21108029 has 4 divisors (see below), whose sum is σ = 21557184. Its totient is φ = 20658876.

The previous prime is 21108007. The next prime is 21108047. The reversal of 21108029 is 92080112.

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 not a de Polignac number, because 21108029 - 2¹² = 21103933 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21107995 and 21108013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21108929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 224507 + ... + 224600.

It is an arithmetic number, because the mean of its divisors is an integer number (5389296).

Almost surely, 2^21108029 is an apocalyptic number.

It is an amenable number.

21108029 is a deficient number, since it is larger than the sum of its proper divisors (449155).

21108029 is an equidigital number, since it uses as much as digits as its factorization.

21108029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449154.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 21108029 is about 4594.3475053592. The cubic root of 21108029 is about 276.3646941556.

The spelling of 21108029 in words is "twenty-one million, one hundred eight thousand, twenty-nine".