1155387785 has 4 divisors (see below), whose sum is σ = 1386465348. Its totient is φ = 924310224.

The previous prime is 1155387767. The next prime is 1155387791. The reversal of 1155387785 is 5877835511.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5877835511 = 5903 ⋅995737.

It can be written as a sum of positive squares in 2 ways, for example, as 600691081 + 554696704 = 24509^2 + 23552^2 .

It is a cyclic number.

It is not a de Polignac number, because 1155387785 - 2⁶ = 1155387721 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, 115538774 + ... + 115538783.

It is an arithmetic number, because the mean of its divisors is an integer number (346616337).

Almost surely, 2^1155387785 is an apocalyptic number.

It is an amenable number.

1155387785 is a deficient number, since it is larger than the sum of its proper divisors (231077563).

1155387785 is an equidigital number, since it uses as much as digits as its factorization.

1155387785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231077562.

The product of its digits is 1176000, while the sum is 50.

The square root of 1155387785 is about 33990.9956459060. The cubic root of 1155387785 is about 1049.3231571410.

The spelling of 1155387785 in words is "one billion, one hundred fifty-five million, three hundred eighty-seven thousand, seven hundred eighty-five".