21828774 has 64 divisors (see below), whose sum is σ = 50429952. Its totient is φ = 6237600.

The previous prime is 21828767. The next prime is 21828791. The reversal of 21828774 is 47782812.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 96049 + ... + 96275.

It is an arithmetic number, because the mean of its divisors is an integer number (787968).

Almost surely, 2^21828774 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21828774, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25214976).

21828774 is an abundant number, since it is smaller than the sum of its proper divisors (28601178).

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

21828774 is a wasteful number, since it uses less digits than its factorization.

21828774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321.

The product of its digits is 50176, while the sum is 39.

The square root of 21828774 is about 4672.1273527163. The cubic root of 21828774 is about 279.4750965338.

The spelling of 21828774 in words is "twenty-one million, eight hundred twenty-eight thousand, seven hundred seventy-four".