21669248 has 64 divisors (see below), whose sum is σ = 45957120. Its totient is φ = 10160640.

The previous prime is 21669239. The next prime is 21669257. The reversal of 21669248 is 84296612.

It is an interprime number because it is at equal distance from previous prime (21669239) and next prime (21669257).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 170561 + ... + 170687.

It is an arithmetic number, because the mean of its divisors is an integer number (718080).

Almost surely, 2^21669248 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 21669248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22978560).

21669248 is an abundant number, since it is smaller than the sum of its proper divisors (24287872).

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

21669248 is a wasteful number, since it uses less digits than its factorization.

21669248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215 (or 203 counting only the distinct ones).

The product of its digits is 41472, while the sum is 38.

The square root of 21669248 is about 4655.0239526774. The cubic root of 21669248 is about 278.7926243411.

The spelling of 21669248 in words is "twenty-one million, six hundred sixty-nine thousand, two hundred forty-eight".