21324808 has 8 divisors (see below), whose sum is σ = 39984030. Its totient is φ = 10662400.

The previous prime is 21324803. The next prime is 21324847. The reversal of 21324808 is 80842312.

It can be written as a sum of positive squares in only one way, i.e., 14760964 + 6563844 = 3842^2 + 2562^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21324803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1332793 + ... + 1332808.

Almost surely, 2^21324808 is an apocalyptic number.

It is an amenable number.

21324808 is a deficient number, since it is larger than the sum of its proper divisors (18659222).

21324808 is a wasteful number, since it uses less digits than its factorization.

21324808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2665607 (or 2665603 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 21324808 is about 4617.8791668904. The cubic root of 21324808 is about 277.3075602179.

The spelling of 21324808 in words is "twenty-one million, three hundred twenty-four thousand, eight hundred eight".