21963648 has 64 divisors (see below), whose sum is σ = 66683520. Its totient is φ = 6274560.

The previous prime is 21963611. The next prime is 21963649. The reversal of 21963648 is 84636912.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21963649) 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, 1398 + ... + 6773.

It is an arithmetic number, because the mean of its divisors is an integer number (1041930).

Almost surely, 2^21963648 is an apocalyptic number.

21963648 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21963648 is an abundant number, since it is smaller than the sum of its proper divisors (44719872).

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

21963648 is an equidigital number, since it uses as much as digits as its factorization.

21963648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8195 (or 8183 counting only the distinct ones).

The product of its digits is 62208, while the sum is 39.

The square root of 21963648 is about 4686.5390214955. The cubic root of 21963648 is about 280.0495150528.

The spelling of 21963648 in words is "twenty-one million, nine hundred sixty-three thousand, six hundred forty-eight".