21246646 has 8 divisors (see below), whose sum is σ = 31951440. Its totient is φ = 10596168.

The previous prime is 21246637. The next prime is 21246683. The reversal of 21246646 is 64664212.

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, 12586 + ... + 14173.

It is an arithmetic number, because the mean of its divisors is an integer number (3993930).

Almost surely, 2^21246646 is an apocalyptic number.

21246646 is a deficient number, since it is larger than the sum of its proper divisors (10704794).

21246646 is a wasteful number, since it uses less digits than its factorization.

21246646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27158.

The product of its digits is 13824, while the sum is 31.

The square root of 21246646 is about 4609.4084219127. The cubic root of 21246646 is about 276.9683395111.

The spelling of 21246646 in words is "twenty-one million, two hundred forty-six thousand, six hundred forty-six".