21004366 has 8 divisors (see below), whose sum is σ = 31977000. Its totient is φ = 10345368.

The previous prime is 21004351. The next prime is 21004387. The reversal of 21004366 is 66340012.

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

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 78241 + ... + 78508.

It is an arithmetic number, because the mean of its divisors is an integer number (3997125).

Almost surely, 2^21004366 is an apocalyptic number.

21004366 is a deficient number, since it is larger than the sum of its proper divisors (10972634).

21004366 is a wasteful number, since it uses less digits than its factorization.

21004366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156818.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 21004366 is about 4583.0520398529. The cubic root of 21004366 is about 275.9115360957.

Adding to 21004366 its reverse (66340012), we get a palindrome (87344378).

The spelling of 21004366 in words is "twenty-one million, four thousand, three hundred sixty-six".