21358040 has 32 divisors (see below), whose sum is σ = 52425360. Its totient is φ = 7766400.

The previous prime is 21358037. The next prime is 21358063. The reversal of 21358040 is 4085312.

It is a junction number, because it is equal to n+sod(n) for n = 21357997 and 21358015.

It is a congruent number.

It is an unprimeable number.

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, 23831 + ... + 24710.

Almost surely, 2^21358040 is an apocalyptic number.

21358040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21358040 is an abundant number, since it is smaller than the sum of its proper divisors (31067320).

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

21358040 is a wasteful number, since it uses less digits than its factorization.

21358040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48563 (or 48559 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21358040 is about 4621.4759547140. The cubic root of 21358040 is about 277.4515349715.

The spelling of 21358040 in words is "twenty-one million, three hundred fifty-eight thousand, forty".