1089855 has 56 divisors (see below), whose sum is σ = 2203488. Its totient is φ = 513216.

The previous prime is 1089841. The next prime is 1089863. The reversal of 1089855 is 5589801.

It is not a de Polignac number, because 1089855 - 2¹⁰ = 1088831 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 47374 + ... + 47396.

It is an arithmetic number, because the mean of its divisors is an integer number (39348).

2^1089855 is an apocalyptic number.

1089855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1089855 is an abundant number, since it is smaller than the sum of its proper divisors (1113633).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1089855 is an equidigital number, since it uses as much as digits as its factorization.

1089855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 36.

The square root of 1089855 is about 1043.9612061758. The cubic root of 1089855 is about 102.9096829790.

The spelling of 1089855 in words is "one million, eighty-nine thousand, eight hundred fifty-five".