1220261209 has 4 divisors (see below), whose sum is σ = 1227314916. Its totient is φ = 1213207504.

The previous prime is 1220261197. The next prime is 1220261227. The reversal of 1220261209 is 9021620221.

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

It can be written as a sum of positive squares in 2 ways, for example, as 891201609 + 329059600 = 29853^2 + 18140^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220261209 - 2²³ = 1211872601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1220261299) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3526594 + ... + 3526939.

It is an arithmetic number, because the mean of its divisors is an integer number (306828729).

Almost surely, 2^1220261209 is an apocalyptic number.

It is an amenable number.

1220261209 is a deficient number, since it is larger than the sum of its proper divisors (7053707).

1220261209 is an equidigital number, since it uses as much as digits as its factorization.

1220261209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7053706.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1220261209 is about 34932.2373889793. The cubic root of 1220261209 is about 1068.6059841557.

The spelling of 1220261209 in words is "one billion, two hundred twenty million, two hundred sixty-one thousand, two hundred nine".