1161855 has 12 divisors (see below), whose sum is σ = 2013960. Its totient is φ = 619632.

The previous prime is 1161851. The next prime is 1161857. The reversal of 1161855 is 5581611.

It is not a de Polignac number, because 1161855 - 2² = 1161851 is a prime.

1161855 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1161851) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12865 + ... + 12954.

It is an arithmetic number, because the mean of its divisors is an integer number (167830).

2^1161855 is an apocalyptic number.

1161855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1161855 is a deficient number, since it is larger than the sum of its proper divisors (852105).

1161855 is a wasteful number, since it uses less digits than its factorization.

1161855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25830 (or 25827 counting only the distinct ones).

The product of its digits is 1200, while the sum is 27.

The square root of 1161855 is about 1077.8937795534. The cubic root of 1161855 is about 105.1277356991.

It can be divided in two parts, 1161 and 855, that added together give a triangular number (2016 = T₆₃).

The spelling of 1161855 in words is "one million, one hundred sixty-one thousand, eight hundred fifty-five".