21254210 has 16 divisors (see below), whose sum is σ = 38400696. Its totient is φ = 8469888.

The previous prime is 21254183. The next prime is 21254213. The reversal of 21254210 is 1245212.

It can be written as a sum of positive squares in 4 ways, for example, as 14969161 + 6285049 = 3869^2 + 2507^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21254213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1067 + ... + 6606.

Almost surely, 2^21254210 is an apocalyptic number.

21254210 is a deficient number, since it is larger than the sum of its proper divisors (17146486).

21254210 is a wasteful number, since it uses less digits than its factorization.

21254210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7957.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 21254210 is about 4610.2288446454. The cubic root of 21254210 is about 277.0012033642.

Adding to 21254210 its reverse (1245212), we get a palindrome (22499422).

The spelling of 21254210 in words is "twenty-one million, two hundred fifty-four thousand, two hundred ten".