21358536 has 32 divisors (see below), whose sum is σ = 55719360. Its totient is φ = 6809792.

The previous prime is 21358501. The next prime is 21358537. The reversal of 21358536 is 63585312.

It is a junction number, because it is equal to n+sod(n) for n = 21358497 and 21358506.

It is not an unprimeable number, because it can be changed into a prime (21358537) 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, 18795 + ... + 19898.

It is an arithmetic number, because the mean of its divisors is an integer number (1741230).

Almost surely, 2^21358536 is an apocalyptic number.

It is an amenable number.

21358536 is an abundant number, since it is smaller than the sum of its proper divisors (34360824).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21358536 is a wasteful number, since it uses less digits than its factorization.

21358536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38725 (or 38721 counting only the distinct ones).

The product of its digits is 21600, while the sum is 33.

The square root of 21358536 is about 4621.5296169126. The cubic root of 21358536 is about 277.4536827169.

The spelling of 21358536 in words is "twenty-one million, three hundred fifty-eight thousand, five hundred thirty-six".