21802438 has 16 divisors (see below), whose sum is σ = 37573920. Its totient is φ = 9294336.

The previous prime is 21802411. The next prime is 21802439. The reversal of 21802438 is 83420812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21802439) 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, 1333 + ... + 6736.

It is an arithmetic number, because the mean of its divisors is an integer number (2348370).

Almost surely, 2^21802438 is an apocalyptic number.

21802438 is a deficient number, since it is larger than the sum of its proper divisors (15771482).

21802438 is a wasteful number, since it uses less digits than its factorization.

21802438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8271.

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 21802438 is about 4669.3080857874. The cubic root of 21802438 is about 279.3626575098.

The spelling of 21802438 in words is "twenty-one million, eight hundred two thousand, four hundred thirty-eight".