21000246 has 8 divisors (see below), whose sum is σ = 42000504. Its totient is φ = 7000080.

The previous prime is 21000233. The next prime is 21000251. The reversal of 21000246 is 64200012.

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

21000246 is an admirable number.

21000246 is a modest number, since divided by 246 gives 210 as remainder.

It is a Curzon number.

It is a congruent number.

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, 1750015 + ... + 1750026.

It is an arithmetic number, because the mean of its divisors is an integer number (5250063).

Almost surely, 2^21000246 is an apocalyptic number.

21000246 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21000246 is a wasteful number, since it uses less digits than its factorization.

21000246 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3500046.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21000246 is about 4582.6025356777. The cubic root of 21000246 is about 275.8934949281.

Adding to 21000246 its reverse (64200012), we get a palindrome (85200258).

The spelling of 21000246 in words is "twenty-one million, two hundred forty-six", and thus it is an aban number.