21302205 has 16 divisors (see below), whose sum is σ = 34167744. Its totient is φ = 11333120.

The previous prime is 21302191. The next prime is 21302219. The reversal of 21302205 is 50220312.

It is an interprime number because it is at equal distance from previous prime (21302191) and next prime (21302219).

It is not a de Polignac number, because 21302205 - 2⁴ = 21302189 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

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 15 ways as a sum of consecutive naturals, for example, 5485 + ... + 8525.

It is an arithmetic number, because the mean of its divisors is an integer number (2135484).

Almost surely, 2^21302205 is an apocalyptic number.

It is an amenable number.

21302205 is a deficient number, since it is larger than the sum of its proper divisors (12865539).

21302205 is a wasteful number, since it uses less digits than its factorization.

21302205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3516.

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 21302205 is about 4615.4311824574. The cubic root of 21302205 is about 277.2095491964.

Adding to 21302205 its reverse (50220312), we get a palindrome (71522517).

The spelling of 21302205 in words is "twenty-one million, three hundred two thousand, two hundred five".