1166561355 has 16 divisors (see below), whose sum is σ = 1868931360. Its totient is φ = 621355008.

The previous prime is 1166561353. The next prime is 1166561371. The reversal of 1166561355 is 5531656611.

It is not a de Polignac number, because 1166561355 - 2¹ = 1166561353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1166561351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38710 + ... + 61899.

It is an arithmetic number, because the mean of its divisors is an integer number (116808210).

Almost surely, 2^1166561355 is an apocalyptic number.

1166561355 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1166561355 is a deficient number, since it is larger than the sum of its proper divisors (702370005).

1166561355 is a wasteful number, since it uses less digits than its factorization.

1166561355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101390.

The product of its digits is 81000, while the sum is 39.

The square root of 1166561355 is about 34154.9609134603. The cubic root of 1166561355 is about 1052.6949231155.

The spelling of 1166561355 in words is "one billion, one hundred sixty-six million, five hundred sixty-one thousand, three hundred fifty-five".