21046205 has 8 divisors (see below), whose sum is σ = 26584800. Its totient is φ = 15950736.

The previous prime is 21046171. The next prime is 21046217. The reversal of 21046205 is 50264012.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21046205 is a prime.

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 7 ways as a sum of consecutive naturals, for example, 110675 + ... + 110864.

It is an arithmetic number, because the mean of its divisors is an integer number (3323100).

Almost surely, 2^21046205 is an apocalyptic number.

It is an amenable number.

21046205 is a deficient number, since it is larger than the sum of its proper divisors (5538595).

21046205 is a wasteful number, since it uses less digits than its factorization.

21046205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221563.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21046205 is about 4587.6143037531. The cubic root of 21046205 is about 276.0946124208.

The spelling of 21046205 in words is "twenty-one million, forty-six thousand, two hundred five".