1216845 has 24 divisors (see below), whose sum is σ = 2411136. Its totient is φ = 556128.

The previous prime is 1216841. The next prime is 1216847. The reversal of 1216845 is 5486121.

1216845 = T₅ + T₆ + ... + T₁₉₃.

It is not a de Polignac number, because 1216845 - 2² = 1216841 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1617 + ... + 2246.

It is an arithmetic number, because the mean of its divisors is an integer number (100464).

2^1216845 is an apocalyptic number.

1216845 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1216845 is a deficient number, since it is larger than the sum of its proper divisors (1194291).

1216845 is a wasteful number, since it uses less digits than its factorization.

1216845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3881 (or 3878 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 1216845 is about 1103.1069757734. The cubic root of 1216845 is about 106.7607839018.

The spelling of 1216845 in words is "one million, two hundred sixteen thousand, eight hundred forty-five".