21405796 has 12 divisors (see below), whose sum is σ = 37618560. Its totient is φ = 10657640.

The previous prime is 21405773. The next prime is 21405803. The reversal of 21405796 is 69750412.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10240 + ... + 12151.

It is an arithmetic number, because the mean of its divisors is an integer number (3134880).

Almost surely, 2^21405796 is an apocalyptic number.

It is an amenable number.

21405796 is a deficient number, since it is larger than the sum of its proper divisors (16212764).

21405796 is a wasteful number, since it uses less digits than its factorization.

21405796 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22634 (or 22632 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 21405796 is about 4626.6398174053. The cubic root of 21405796 is about 277.6581724130.

It can be divided in two parts, 21405 and 796, that added together give a square (22201 = 149²).

The spelling of 21405796 in words is "twenty-one million, four hundred five thousand, seven hundred ninety-six".