21147206 has 8 divisors (see below), whose sum is σ = 32814720. Its totient is φ = 10208968.

The previous prime is 21147197. The next prime is 21147211. The reversal of 21147206 is 60274112.

It is a sphenic number, since it is the product of 3 distinct primes.

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 3 ways as a sum of consecutive naturals, for example, 182246 + ... + 182361.

It is an arithmetic number, because the mean of its divisors is an integer number (4101840).

Almost surely, 2^21147206 is an apocalyptic number.

21147206 is a deficient number, since it is larger than the sum of its proper divisors (11667514).

21147206 is a wasteful number, since it uses less digits than its factorization.

21147206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364638.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 21147206 is about 4598.6091375545. The cubic root of 21147206 is about 276.5355682820.

The spelling of 21147206 in words is "twenty-one million, one hundred forty-seven thousand, two hundred six".