21298368 has 224 divisors, whose sum is σ = 73737216. Its totient is φ = 5271552.

The previous prime is 21298363. The next prime is 21298369. The reversal of 21298368 is 86389212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Smith number, since the sum of its digits (39) 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 (39).

It is not an unprimeable number, because it can be changed into a prime (21298363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 401830 + ... + 401882.

It is an arithmetic number, because the mean of its divisors is an integer number (329184).

Almost surely, 2^21298368 is an apocalyptic number.

21298368 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 21298368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36868608).

21298368 is an abundant number, since it is smaller than the sum of its proper divisors (52438848).

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

21298368 is a wasteful number, since it uses less digits than its factorization.

21298368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111 (or 101 counting only the distinct ones).

The product of its digits is 41472, while the sum is 39.

The square root of 21298368 is about 4615.0154929317. The cubic root of 21298368 is about 277.1929043325.

The spelling of 21298368 in words is "twenty-one million, two hundred ninety-eight thousand, three hundred sixty-eight".