1155221605009 has 2 divisors, whose sum is σ = 1155221605010. Its totient is φ = 1155221605008.

The previous prime is 1155221605007. The next prime is 1155221605019. The reversal of 1155221605009 is 9005061225511.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 989676780625 + 165544824384 = 994825^2 + 406872^2 .

It is a cyclic number.

It is not a de Polignac number, because 1155221605009 - 2¹ = 1155221605007 is a prime.

Together with 1155221605007, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1155221605007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 577610802504 + 577610802505.

It is an arithmetic number, because the mean of its divisors is an integer number (577610802505).

Almost surely, 2^{1155221605009} is an apocalyptic number.

It is an amenable number.

1155221605009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1155221605009 is an equidigital number, since it uses as much as digits as its factorization.

1155221605009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27000, while the sum is 37.

The spelling of 1155221605009 in words is "one trillion, one hundred fifty-five billion, two hundred twenty-one million, six hundred five thousand, nine".