21725606 has 32 divisors (see below), whose sum is σ = 38873088. Its totient is φ = 8910720.

The previous prime is 21725581. The next prime is 21725617. The reversal of 21725606 is 60652712.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

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 in 15 ways as a sum of consecutive naturals, for example, 48821 + ... + 49263.

It is an arithmetic number, because the mean of its divisors is an integer number (1214784).

Almost surely, 2^21725606 is an apocalyptic number.

21725606 is a deficient number, since it is larger than the sum of its proper divisors (17147482).

21725606 is a wasteful number, since it uses less digits than its factorization.

21725606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 21725606 is about 4661.0734815062. The cubic root of 21725606 is about 279.0341123829.

The spelling of 21725606 in words is "twenty-one million, seven hundred twenty-five thousand, six hundred six".