1218825 has 18 divisors (see below), whose sum is σ = 2183454. Its totient is φ = 649920.

The previous prime is 1218821. The next prime is 1218829. The reversal of 1218825 is 5288121.

It is an interprime number because it is at equal distance from previous prime (1218821) and next prime (1218829).

It can be written as a sum of positive squares in 3 ways, for example, as 9 + 1218816 = 3^2 + 1104^2 .

It is not a de Polignac number, because 1218825 - 2² = 1218821 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1218821) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2484 + ... + 2933.

It is an arithmetic number, because the mean of its divisors is an integer number (121303).

2^1218825 is an apocalyptic number.

1218825 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1218825 is a deficient number, since it is larger than the sum of its proper divisors (964629).

1218825 is a wasteful number, since it uses less digits than its factorization.

1218825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5433 (or 5425 counting only the distinct ones).

The product of its digits is 1280, while the sum is 27.

The square root of 1218825 is about 1104.0040760794. The cubic root of 1218825 is about 106.8186581045.

The spelling of 1218825 in words is "one million, two hundred eighteen thousand, eight hundred twenty-five".