21585385 has 8 divisors (see below), whose sum is σ = 27028800. Its totient is φ = 16517424.

The previous prime is 21585371. The next prime is 21585391. The reversal of 21585385 is 58358512.

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 21585385 - 2¹⁹ = 21061097 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 93735 + ... + 93964.

It is an arithmetic number, because the mean of its divisors is an integer number (3378600).

Almost surely, 2^21585385 is an apocalyptic number.

It is an amenable number.

21585385 is a deficient number, since it is larger than the sum of its proper divisors (5443415).

21585385 is a wasteful number, since it uses less digits than its factorization.

21585385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187727.

The product of its digits is 48000, while the sum is 37.

The square root of 21585385 is about 4646.0074257366. The cubic root of 21585385 is about 278.4325039737.

The spelling of 21585385 in words is "twenty-one million, five hundred eighty-five thousand, three hundred eighty-five".