1221135305 has 8 divisors (see below), whose sum is σ = 1578082632. Its totient is φ = 901761408.

The previous prime is 1221135299. The next prime is 1221135323. The reversal of 1221135305 is 5035311221.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3055504 + 1218079801 = 1748^2 + 34901^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1221135305 - 2⁶ = 1221135241 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9393284 + ... + 9393413.

It is an arithmetic number, because the mean of its divisors is an integer number (197260329).

Almost surely, 2^1221135305 is an apocalyptic number.

It is an amenable number.

1221135305 is a deficient number, since it is larger than the sum of its proper divisors (356947327).

1221135305 is a wasteful number, since it uses less digits than its factorization.

1221135305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18786715.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 1221135305 is about 34944.7464578011. The cubic root of 1221135305 is about 1068.8610774283.

Adding to 1221135305 its reverse (5035311221), we get a palindrome (6256446526).

The spelling of 1221135305 in words is "one billion, two hundred twenty-one million, one hundred thirty-five thousand, three hundred five".