1200855 has 16 divisors (see below), whose sum is σ = 1935360. Its totient is φ = 635808.

The previous prime is 1200839. The next prime is 1200869. The reversal of 1200855 is 5580021.

It is not a de Polignac number, because 1200855 - 2⁴ = 1200839 is a prime.

1200855 is a lucky number.

It is a congruent number.

It is an unprimeable number.

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, 3166 + ... + 3524.

It is an arithmetic number, because the mean of its divisors is an integer number (120960).

2^1200855 is an apocalyptic number.

1200855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1200855 is a deficient number, since it is larger than the sum of its proper divisors (734505).

1200855 is a wasteful number, since it uses less digits than its factorization.

1200855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 590.

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 1200855 is about 1095.8352978436. The cubic root of 1200855 is about 106.2910890676.

Adding to 1200855 its reverse (5580021), we get a palindrome (6780876).

The spelling of 1200855 in words is "one million, two hundred thousand, eight hundred fifty-five".