21493585 has 8 divisors (see below), whose sum is σ = 25900776. Its totient is φ = 17122560.

The previous prime is 21493583. The next prime is 21493603. The reversal of 21493585 is 58539412.

It can be written as a sum of positive squares in 4 ways, for example, as 7884864 + 13608721 = 2808^2 + 3689^2 .

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

It is not a de Polignac number, because 21493585 - 2¹ = 21493583 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21493583) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7714 + ... + 10123.

It is an arithmetic number, because the mean of its divisors is an integer number (3237597).

Almost surely, 2^21493585 is an apocalyptic number.

It is an amenable number.

21493585 is a deficient number, since it is larger than the sum of its proper divisors (4407191).

21493585 is a wasteful number, since it uses less digits than its factorization.

21493585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18083.

The product of its digits is 43200, while the sum is 37.

The square root of 21493585 is about 4636.1174489005. The cubic root of 21493585 is about 278.0372299741.

The spelling of 21493585 in words is "twenty-one million, four hundred ninety-three thousand, five hundred eighty-five".