21384029 has 4 divisors (see below), whose sum is σ = 21881376. Its totient is φ = 20886684.

The previous prime is 21383969. The next prime is 21384061. The reversal of 21384029 is 92048312.

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 21384029 - 2¹² = 21379933 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21383992 and 21384010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21384229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 248609 + ... + 248694.

It is an arithmetic number, because the mean of its divisors is an integer number (5470344).

Almost surely, 2^21384029 is an apocalyptic number.

It is an amenable number.

21384029 is a deficient number, since it is larger than the sum of its proper divisors (497347).

21384029 is an equidigital number, since it uses as much as digits as its factorization.

21384029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497346.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 21384029 is about 4624.2868639391. The cubic root of 21384029 is about 277.5640260241.

The spelling of 21384029 in words is "twenty-one million, three hundred eighty-four thousand, twenty-nine".