1355555809 has 4 divisors (see below), whose sum is σ = 1435294404. Its totient is φ = 1275817216.

The previous prime is 1355555783. The next prime is 1355555813. The reversal of 1355555809 is 9085555531.

It is a happy number.

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 668067409 + 687488400 = 25847^2 + 26220^2 .

It is a cyclic number.

It is not a de Polignac number, because 1355555809 - 2⁷ = 1355555681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1355555819) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 39869272 + ... + 39869305.

It is an arithmetic number, because the mean of its divisors is an integer number (358823601).

Almost surely, 2^1355555809 is an apocalyptic number.

It is an amenable number.

1355555809 is a deficient number, since it is larger than the sum of its proper divisors (79738595).

1355555809 is an equidigital number, since it uses as much as digits as its factorization.

1355555809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79738594.

The product of its (nonzero) digits is 675000, while the sum is 46.

The square root of 1355555809 is about 36817.8734991580. The cubic root of 1355555809 is about 1106.7235060059.

The spelling of 1355555809 in words is "one billion, three hundred fifty-five million, five hundred fifty-five thousand, eight hundred nine".