211221330 has 16 divisors (see below), whose sum is σ = 506931264. Its totient is φ = 56325680.

The previous prime is 211221313. The next prime is 211221331. The reversal of 211221330 is 33122112.

It is a super-2 number, since 2×211221330² = 89228900493937800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (211221331) 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, 3520326 + ... + 3520385.

It is an arithmetic number, because the mean of its divisors is an integer number (31683204).

Almost surely, 2^211221330 is an apocalyptic number.

211221330 is an abundant number, since it is smaller than the sum of its proper divisors (295709934).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

211221330 is a wasteful number, since it uses less digits than its factorization.

211221330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7040721.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 211221330 is about 14533.4555422996. The cubic root of 211221330 is about 595.5422686269.

Adding to 211221330 its reverse (33122112), we get a palindrome (244343442).

The spelling of 211221330 in words is "two hundred eleven million, two hundred twenty-one thousand, three hundred thirty".