21443836 has 12 divisors (see below), whose sum is σ = 37570680. Its totient is φ = 10709360.

The previous prime is 21443827. The next prime is 21443881. The reversal of 21443836 is 63834412.

It is a junction number, because it is equal to n+sod(n) for n = 21443798 and 21443807.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1446 + ... + 6706.

It is an arithmetic number, because the mean of its divisors is an integer number (3130890).

Almost surely, 2^21443836 is an apocalyptic number.

It is an amenable number.

21443836 is a deficient number, since it is larger than the sum of its proper divisors (16126844).

21443836 is a wasteful number, since it uses less digits than its factorization.

21443836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6284 (or 6282 counting only the distinct ones).

The product of its digits is 13824, while the sum is 31.

The square root of 21443836 is about 4630.7489674997. The cubic root of 21443836 is about 277.8225494886.

The spelling of 21443836 in words is "twenty-one million, four hundred forty-three thousand, eight hundred thirty-six".