21150305 has 16 divisors (see below), whose sum is σ = 27820800. Its totient is φ = 15308160.

The previous prime is 21150293. The next prime is 21150313. The reversal of 21150305 is 50305112.

It is not a de Polignac number, because 21150305 - 2⁴ = 21150289 is a prime.

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 15 ways as a sum of consecutive naturals, for example, 12341 + ... + 13949.

It is an arithmetic number, because the mean of its divisors is an integer number (1738800).

Almost surely, 2^21150305 is an apocalyptic number.

It is an amenable number.

21150305 is a deficient number, since it is larger than the sum of its proper divisors (6670495).

21150305 is a wasteful number, since it uses less digits than its factorization.

21150305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1864.

The product of its (nonzero) digits is 150, while the sum is 17.

The square root of 21150305 is about 4598.9460749176. The cubic root of 21150305 is about 276.5490758484.

Adding to 21150305 its reverse (50305112), we get a palindrome (71455417).

The spelling of 21150305 in words is "twenty-one million, one hundred fifty thousand, three hundred five".