21211330 has 16 divisors (see below), whose sum is σ = 43634880. Its totient is φ = 7272432.

The previous prime is 21211319. The next prime is 21211339. The reversal of 21211330 is 3311212.

It is a self number, because there is not a number n which added to its sum of digits gives 21211330.

It is not an unprimeable number, because it can be changed into a prime (21211339) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 151440 + ... + 151579.

It is an arithmetic number, because the mean of its divisors is an integer number (2727180).

Almost surely, 2^21211330 is an apocalyptic number.

21211330 is an abundant number, since it is smaller than the sum of its proper divisors (22423550).

21211330 is a wasteful number, since it uses less digits than its factorization.

21211330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303033.

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

The square root of 21211330 is about 4605.5759683236. The cubic root of 21211330 is about 276.8147962426.

Adding to 21211330 its reverse (3311212), we get a palindrome (24522542).

The spelling of 21211330 in words is "twenty-one million, two hundred eleven thousand, three hundred thirty".