1161171555 has 32 divisors (see below), whose sum is σ = 1922773248. Its totient is φ = 597916800.

The previous prime is 1161171509. The next prime is 1161171589. The reversal of 1161171555 is 5551711611.

It is not a de Polignac number, because 1161171555 - 2⁸ = 1161171299 is a prime.

It is a super-3 number, since 3×1161171555³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 64720 + ... + 80690.

It is an arithmetic number, because the mean of its divisors is an integer number (60086664).

Almost surely, 2^1161171555 is an apocalyptic number.

1161171555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1161171555 is a deficient number, since it is larger than the sum of its proper divisors (761601693).

1161171555 is a wasteful number, since it uses less digits than its factorization.

1161171555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16147.

The product of its digits is 5250, while the sum is 33.

The square root of 1161171555 is about 34075.9674110655. The cubic root of 1161171555 is about 1051.0711834780.

The spelling of 1161171555 in words is "one billion, one hundred sixty-one million, one hundred seventy-one thousand, five hundred fifty-five".