21797248 has 64 divisors (see below), whose sum is σ = 48139920. Its totient is φ = 9748480.

The previous prime is 21797233. The next prime is 21797249. The reversal of 21797248 is 84279712.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 21797248.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21797249) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 159036 + ... + 159172.

Almost surely, 2^21797248 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 21797248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24069960).

21797248 is an abundant number, since it is smaller than the sum of its proper divisors (26342672).

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

21797248 is a wasteful number, since it uses less digits than its factorization.

21797248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275 (or 263 counting only the distinct ones).

The product of its digits is 56448, while the sum is 40.

The square root of 21797248 is about 4668.7522958495. The cubic root of 21797248 is about 279.3404886243.

The spelling of 21797248 in words is "twenty-one million, seven hundred ninety-seven thousand, two hundred forty-eight".