21493604 has 24 divisors (see below), whose sum is σ = 41277600. Its totient is φ = 9711680.

The previous prime is 21493603. The next prime is 21493613. The reversal of 21493604 is 40639412.

It is not an unprimeable number, because it can be changed into a prime (21493603) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6512 + ... + 9240.

It is an arithmetic number, because the mean of its divisors is an integer number (1719900).

Almost surely, 2^21493604 is an apocalyptic number.

It is an amenable number.

21493604 is a deficient number, since it is larger than the sum of its proper divisors (19783996).

21493604 is a wasteful number, since it uses less digits than its factorization.

21493604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2923 (or 2921 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 21493604 is about 4636.1194980285. The cubic root of 21493604 is about 278.0373119010.

The spelling of 21493604 in words is "twenty-one million, four hundred ninety-three thousand, six hundred four".