21546648 has 80 divisors (see below), whose sum is σ = 61898760. Its totient is φ = 6998400.

The previous prime is 21546647. The next prime is 21546649. The reversal of 21546648 is 84664512.

21546648 is a `hidden beast` number, since 2 + 1 + 5 + 4 + 6 + 648 = 666.

It is an interprime number because it is at equal distance from previous prime (21546647) and next prime (21546649).

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

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21546641) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 26163 + ... + 26973.

Almost surely, 2^21546648 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 21546648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30949380).

21546648 is an abundant number, since it is smaller than the sum of its proper divisors (40352112).

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

21546648 is a wasteful number, since it uses less digits than its factorization.

21546648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 870 (or 857 counting only the distinct ones).

The product of its digits is 46080, while the sum is 36.

The square root of 21546648 is about 4641.8367054432. The cubic root of 21546648 is about 278.2658464831.

The spelling of 21546648 in words is "twenty-one million, five hundred forty-six thousand, six hundred forty-eight".