1211985 has 24 divisors (see below), whose sum is σ = 2193984. Its totient is φ = 617760.

The previous prime is 1211983. The next prime is 1211999. The reversal of 1211985 is 5891121.

It is not a de Polignac number, because 1211985 - 2¹ = 1211983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1211983) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 450 + ... + 1620.

It is an arithmetic number, because the mean of its divisors is an integer number (91416).

2^1211985 is an apocalyptic number.

1211985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1211985 is a deficient number, since it is larger than the sum of its proper divisors (981999).

1211985 is a wasteful number, since it uses less digits than its factorization.

1211985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1205 (or 1202 counting only the distinct ones).

The product of its digits is 720, while the sum is 27.

The square root of 1211985 is about 1100.9019029868. The cubic root of 1211985 is about 106.6184623770.

The spelling of 1211985 in words is "one million, two hundred eleven thousand, nine hundred eighty-five".