21793439 has 8 divisors (see below), whose sum is σ = 23293008. Its totient is φ = 20318080.

The previous prime is 21793363. The next prime is 21793451. The reversal of 21793439 is 93439712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21793439 - 2⁸ = 21793183 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21793459) 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 7 ways as a sum of consecutive naturals, for example, 4172 + ... + 7809.

It is an arithmetic number, because the mean of its divisors is an integer number (2911626).

Almost surely, 2^21793439 is an apocalyptic number.

21793439 is a deficient number, since it is larger than the sum of its proper divisors (1499569).

21793439 is a wasteful number, since it uses less digits than its factorization.

21793439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12105.

The product of its digits is 40824, while the sum is 38.

The square root of 21793439 is about 4668.3443531942. The cubic root of 21793439 is about 279.3242163881.

The spelling of 21793439 in words is "twenty-one million, seven hundred ninety-three thousand, four hundred thirty-nine".