21004359 has 8 divisors (see below), whose sum is σ = 29223552. Its totient is φ = 13394040.

The previous prime is 21004351. The next prime is 21004387. The reversal of 21004359 is 95340012.

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

It is not a de Polignac number, because 21004359 - 2³ = 21004351 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21004351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152137 + ... + 152274.

It is an arithmetic number, because the mean of its divisors is an integer number (3652944).

Almost surely, 2^21004359 is an apocalyptic number.

21004359 is a deficient number, since it is larger than the sum of its proper divisors (8219193).

21004359 is a wasteful number, since it uses less digits than its factorization.

21004359 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304437.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 21004359 is about 4583.0512761696. The cubic root of 21004359 is about 275.9115054452.

The spelling of 21004359 in words is "twenty-one million, four thousand, three hundred fifty-nine".