1200665555 has 4 divisors (see below), whose sum is σ = 1440798672. Its totient is φ = 960532440.

The previous prime is 1200665519. The next prime is 1200665561. The reversal of 1200665555 is 5555660021.

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

It is not a de Polignac number, because 1200665555 - 2⁸ = 1200665299 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120066551 + ... + 120066560.

It is an arithmetic number, because the mean of its divisors is an integer number (360199668).

Almost surely, 2^1200665555 is an apocalyptic number.

1200665555 is a deficient number, since it is larger than the sum of its proper divisors (240133117).

1200665555 is an equidigital number, since it uses as much as digits as its factorization.

1200665555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240133116.

The product of its (nonzero) digits is 45000, while the sum is 35.

The square root of 1200665555 is about 34650.6212787015. The cubic root of 1200665555 is about 1062.8549933518.

The spelling of 1200665555 in words is "one billion, two hundred million, six hundred sixty-five thousand, five hundred fifty-five".