21653936 has 10 divisors (see below), whose sum is σ = 41954532. Its totient is φ = 10826960.

The previous prime is 21653927. The next prime is 21653941. The reversal of 21653936 is 63935612.

It is a junction number, because it is equal to n+sod(n) for n = 21653896 and 21653905.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 676670 + ... + 676701.

Almost surely, 2^21653936 is an apocalyptic number.

It is an amenable number.

21653936 is a deficient number, since it is larger than the sum of its proper divisors (20300596).

21653936 is a wasteful number, since it uses less digits than its factorization.

21653936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1353379 (or 1353373 counting only the distinct ones).

The product of its digits is 29160, while the sum is 35.

The square root of 21653936 is about 4653.3789873596. The cubic root of 21653936 is about 278.7269417272.

The spelling of 21653936 in words is "twenty-one million, six hundred fifty-three thousand, nine hundred thirty-six".