21874236 has 48 divisors (see below), whose sum is σ = 53222400. Its totient is φ = 6983872.

The previous prime is 21874199. The next prime is 21874241. The reversal of 21874236 is 63247812.

It is a junction number, because it is equal to n+sod(n) for n = 21874197 and 21874206.

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 15 ways as a sum of consecutive naturals, for example, 83041 + ... + 83303.

It is an arithmetic number, because the mean of its divisors is an integer number (1108800).

Almost surely, 2^21874236 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21874236, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26611200).

21874236 is an abundant number, since it is smaller than the sum of its proper divisors (31348164).

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

21874236 is a wasteful number, since it uses less digits than its factorization.

21874236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538 (or 536 counting only the distinct ones).

The product of its digits is 16128, while the sum is 33.

The square root of 21874236 is about 4676.9900577187. The cubic root of 21874236 is about 279.6689795649.

The spelling of 21874236 in words is "twenty-one million, eight hundred seventy-four thousand, two hundred thirty-six".