21504064 has 28 divisors (see below), whose sum is σ = 42861484. Its totient is φ = 10704384.

The previous prime is 21504053. The next prime is 21504083. The reversal of 21504064 is 46040512.

It can be written as a sum of positive squares in 2 ways, for example, as 2073600 + 19430464 = 1440^2 + 4408^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17122 + ... + 18334.

Almost surely, 2^21504064 is an apocalyptic number.

It is an amenable number.

21504064 is a deficient number, since it is larger than the sum of its proper divisors (21357420).

21504064 is a wasteful number, since it uses less digits than its factorization.

21504064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1502 (or 1492 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 21504064 is about 4637.2474594311. The cubic root of 21504064 is about 278.0824074658.

Adding to 21504064 its reverse (46040512), we get a palindrome (67544576).

The spelling of 21504064 in words is "twenty-one million, five hundred four thousand, sixty-four".