21847968 has 60 divisors (see below), whose sum is σ = 64261890. Its totient is φ = 7281792.

The previous prime is 21847961. The next prime is 21847993. The reversal of 21847968 is 86974812.

It can be written as a sum of positive squares in only one way, i.e., 20903184 + 944784 = 4572^2 + 972^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21847961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1623 + ... + 6806.

Almost surely, 2^21847968 is an apocalyptic number.

It is an amenable number.

21847968 is an abundant number, since it is smaller than the sum of its proper divisors (42413922).

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

21847968 is an equidigital number, since it uses as much as digits as its factorization.

21847968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8451 (or 8434 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 21847968 is about 4674.1809977792. The cubic root of 21847968 is about 279.5569865125.

The spelling of 21847968 in words is "twenty-one million, eight hundred forty-seven thousand, nine hundred sixty-eight".