21053648 has 80 divisors (see below), whose sum is σ = 53139456. Its totient is φ = 7835520.

The previous prime is 21053639. The next prime is 21053651. The reversal of 21053648 is 84635012.

It is a super-3 number, since 3×21053648³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21053648.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27965 + ... + 28707.

Almost surely, 2^21053648 is an apocalyptic number.

21053648 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21053648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26569728).

21053648 is an abundant number, since it is smaller than the sum of its proper divisors (32085808).

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

21053648 is a wasteful number, since it uses less digits than its factorization.

21053648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 792 (or 786 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 21053648 is about 4588.4254379907. The cubic root of 21053648 is about 276.1271555800.

The spelling of 21053648 in words is "twenty-one million, fifty-three thousand, six hundred forty-eight".