1221430211 has 4 divisors (see below), whose sum is σ = 1222448424. Its totient is φ = 1220412000.

The previous prime is 1221430201. The next prime is 1221430289. The reversal of 1221430211 is 1120341221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221430211 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221430211.

It is not an unprimeable number, because it can be changed into a prime (1221430201) 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, 507305 + ... + 509706.

It is an arithmetic number, because the mean of its divisors is an integer number (305612106).

Almost surely, 2^1221430211 is an apocalyptic number.

1221430211 is a deficient number, since it is larger than the sum of its proper divisors (1018213).

1221430211 is a wasteful number, since it uses less digits than its factorization.

1221430211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1018212.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 1221430211 is about 34948.9658073025. The cubic root of 1221430211 is about 1068.9471143516.

Adding to 1221430211 its reverse (1120341221), we get a palindrome (2341771432).

The spelling of 1221430211 in words is "one billion, two hundred twenty-one million, four hundred thirty thousand, two hundred eleven".