21206230 has 32 divisors (see below), whose sum is σ = 40181184. Its totient is φ = 8042496.

The previous prime is 21206219. The next prime is 21206233. The reversal of 21206230 is 3260212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21206233) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31174 + ... + 31846.

It is an arithmetic number, because the mean of its divisors is an integer number (1255662).

Almost surely, 2^21206230 is an apocalyptic number.

21206230 is a deficient number, since it is larger than the sum of its proper divisors (18974954).

21206230 is a wasteful number, since it uses less digits than its factorization.

21206230 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 840.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 21206230 is about 4605.0222583610. The cubic root of 21206230 is about 276.7926089081.

Adding to 21206230 its reverse (3260212), we get a palindrome (24466442).

The spelling of 21206230 in words is "twenty-one million, two hundred six thousand, two hundred thirty".