21293648 has 20 divisors (see below), whose sum is σ = 42372660. Its totient is φ = 10358784.

The previous prime is 21293647. The next prime is 21293659. The reversal of 21293648 is 84639212.

It can be written as a sum of positive squares in 2 ways, for example, as 19465744 + 1827904 = 4412^2 + 1352^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21293647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17393 + ... + 18576.

It is an arithmetic number, because the mean of its divisors is an integer number (2118633).

Almost surely, 2^21293648 is an apocalyptic number.

It is an amenable number.

21293648 is a deficient number, since it is larger than the sum of its proper divisors (21079012).

21293648 is a wasteful number, since it uses less digits than its factorization.

21293648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36014 (or 36008 counting only the distinct ones).

The product of its digits is 20736, while the sum is 35.

The square root of 21293648 is about 4614.5040903655. The cubic root of 21293648 is about 277.1724262819.

The spelling of 21293648 in words is "twenty-one million, two hundred ninety-three thousand, six hundred forty-eight".