21316559 has 8 divisors (see below), whose sum is σ = 23289552. Its totient is φ = 19349440.

The previous prime is 21316553. The next prime is 21316579. The reversal of 21316559 is 95561312.

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

It is not a de Polignac number, because 21316559 - 2¹² = 21312463 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21316553) 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, 10187 + ... + 12099.

It is an arithmetic number, because the mean of its divisors is an integer number (2911194).

Almost surely, 2^21316559 is an apocalyptic number.

21316559 is a deficient number, since it is larger than the sum of its proper divisors (1972993).

21316559 is a wasteful number, since it uses less digits than its factorization.

21316559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2937.

The product of its digits is 8100, while the sum is 32.

The square root of 21316559 is about 4616.9859215726. The cubic root of 21316559 is about 277.2717989724.

The spelling of 21316559 in words is "twenty-one million, three hundred sixteen thousand, five hundred fifty-nine".