21052548 has 108 divisors (see below), whose sum is σ = 60999120. Its totient is φ = 6343920.

The previous prime is 21052547. The next prime is 21052553. The reversal of 21052548 is 84525012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (108).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21052547) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 117523 + ... + 117701.

Almost surely, 2^21052548 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 21052548, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30499560).

21052548 is an abundant number, since it is smaller than the sum of its proper divisors (39946572).

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

21052548 is a wasteful number, since it uses less digits than its factorization.

21052548 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220 (or 195 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 21052548 is about 4588.3055695976. The cubic root of 21052548 is about 276.1223465138.

The spelling of 21052548 in words is "twenty-one million, fifty-two thousand, five hundred forty-eight".