1161555394 has 16 divisors (see below), whose sum is σ = 1756096056. Its totient is φ = 576201600.

The previous prime is 1161555391. The next prime is 1161555397. The reversal of 1161555394 is 4935551611.

It is an interprime number because it is at equal distance from previous prime (1161555391) and next prime (1161555397).

It can be written as a sum of positive squares in 4 ways, for example, as 772006225 + 389549169 = 27785^2 + 19737^2 .

It is a super-3 number, since 3×1161555394³ (a number of 28 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1161555391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 236524 + ... + 241384.

Almost surely, 2^1161555394 is an apocalyptic number.

1161555394 is a deficient number, since it is larger than the sum of its proper divisors (594540662).

1161555394 is a wasteful number, since it uses less digits than its factorization.

1161555394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5781.

The product of its digits is 81000, while the sum is 40.

The square root of 1161555394 is about 34081.5990528614. The cubic root of 1161555394 is about 1051.1869853921.

The spelling of 1161555394 in words is "one billion, one hundred sixty-one million, five hundred fifty-five thousand, three hundred ninety-four".