21858048 has 108 divisors (see below), whose sum is σ = 64569960. Its totient is φ = 7108608.

The previous prime is 21858029. The next prime is 21858127. The reversal of 21858048 is 84085812.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 122023 + ... + 122201.

It is an arithmetic number, because the mean of its divisors is an integer number (597870).

Almost surely, 2^21858048 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 21858048, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32284980).

21858048 is an abundant number, since it is smaller than the sum of its proper divisors (42711912).

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

21858048 is a wasteful number, since it uses less digits than its factorization.

21858048 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254 (or 237 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 36.

The square root of 21858048 is about 4675.2591372030. The cubic root of 21858048 is about 279.5999729841.

It can be divided in two parts, 2185804 and 8, that added together give a palindrome (2185812).

The spelling of 21858048 in words is "twenty-one million, eight hundred fifty-eight thousand, forty-eight".