21331210 has 8 divisors (see below), whose sum is σ = 38396196. Its totient is φ = 8532480.

The previous prime is 21331201. The next prime is 21331217. The reversal of 21331210 is 1213312.

It can be written as a sum of positive squares in 2 ways, for example, as 19527561 + 1803649 = 4419^2 + 1343^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21331217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1066551 + ... + 1066570.

Almost surely, 2^21331210 is an apocalyptic number.

21331210 is a deficient number, since it is larger than the sum of its proper divisors (17064986).

21331210 is a wasteful number, since it uses less digits than its factorization.

21331210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2133128.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21331210 is about 4618.5722902213. The cubic root of 21331210 is about 277.3353079530.

Adding to 21331210 its reverse (1213312), we get a palindrome (22544522).

The spelling of 21331210 in words is "twenty-one million, three hundred thirty-one thousand, two hundred ten".