21195648 has 64 divisors (see below), whose sum is σ = 62566800. Its totient is φ = 7064064.

The previous prime is 21195641. The next prime is 21195653. The reversal of 21195648 is 84659112.

21195648 is a `hidden beast` number, since 2 + 1 + 1 + 9 + 5 + 648 = 666.

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

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21195641) 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, 390 + ... + 6522.

Almost surely, 2^21195648 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 21195648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31283400).

21195648 is an abundant number, since it is smaller than the sum of its proper divisors (41371152).

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

21195648 is an equidigital number, since it uses as much as digits as its factorization.

21195648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6156 (or 6138 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 21195648 is about 4603.8731520319. The cubic root of 21195648 is about 276.7465610137.

It can be divided in two parts, 211 and 95648, that added together give a palindrome (95859).

The spelling of 21195648 in words is "twenty-one million, one hundred ninety-five thousand, six hundred forty-eight".