21304648 has 8 divisors (see below), whose sum is σ = 39946230. Its totient is φ = 10652320.

The previous prime is 21304639. The next prime is 21304667. The reversal of 21304648 is 84640312.

It can be written as a sum of positive squares in only one way, i.e., 20811844 + 492804 = 4562^2 + 702^2 .

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 an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1331533 + ... + 1331548.

Almost surely, 2^21304648 is an apocalyptic number.

It is an amenable number.

21304648 is a deficient number, since it is larger than the sum of its proper divisors (18641582).

21304648 is a wasteful number, since it uses less digits than its factorization.

21304648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2663087 (or 2663083 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 21304648 is about 4615.6958305330. The cubic root of 21304648 is about 277.2201458622.

It can be divided in two parts, 21304 and 648, that added together give a cube (21952 = 28³).

The spelling of 21304648 in words is "twenty-one million, three hundred four thousand, six hundred forty-eight".