21209350 has 12 divisors (see below), whose sum is σ = 39449484. Its totient is φ = 8483720.

The previous prime is 21209327. The next prime is 21209359. The reversal of 21209350 is 5390212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21209359) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 212044 + ... + 212143.

It is an arithmetic number, because the mean of its divisors is an integer number (3287457).

Almost surely, 2^21209350 is an apocalyptic number.

21209350 is a deficient number, since it is larger than the sum of its proper divisors (18240134).

21209350 is a wasteful number, since it uses less digits than its factorization.

21209350 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424199 (or 424194 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 22.

The square root of 21209350 is about 4605.3610064793. The cubic root of 21209350 is about 276.8061827586.

Adding to 21209350 its reverse (5390212), we get a palindrome (26599562).

The spelling of 21209350 in words is "twenty-one million, two hundred nine thousand, three hundred fifty".