21385006 has 16 divisors (see below), whose sum is σ = 33319440. Its totient is φ = 10281600.

The previous prime is 21384991. The next prime is 21385057. The reversal of 21385006 is 60058312.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17206 + ... + 18406.

It is an arithmetic number, because the mean of its divisors is an integer number (2082465).

Almost surely, 2^21385006 is an apocalyptic number.

21385006 is a deficient number, since it is larger than the sum of its proper divisors (11934434).

21385006 is a wasteful number, since it uses less digits than its factorization.

21385006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1539.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 21385006 is about 4624.3925006427. The cubic root of 21385006 is about 277.5682531028.

The spelling of 21385006 in words is "twenty-one million, three hundred eighty-five thousand, six".