21445836 has 24 divisors (see below), whose sum is σ = 50529024. Its totient is φ = 7078800.

The previous prime is 21445807. The next prime is 21445847. The reversal of 21445836 is 63854412.

It is a junction number, because it is equal to n+sod(n) for n = 21445797 and 21445806.

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, 7440 + ... + 9911.

It is an arithmetic number, because the mean of its divisors is an integer number (2105376).

Almost surely, 2^21445836 is an apocalyptic number.

It is an amenable number.

21445836 is an abundant number, since it is smaller than the sum of its proper divisors (29083188).

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

21445836 is a wasteful number, since it uses less digits than its factorization.

21445836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17461 (or 17459 counting only the distinct ones).

The product of its digits is 23040, while the sum is 33.

The square root of 21445836 is about 4630.9649102536. The cubic root of 21445836 is about 277.8311864356.

The spelling of 21445836 in words is "twenty-one million, four hundred forty-five thousand, eight hundred thirty-six".