1220818 has 4 divisors (see below), whose sum is σ = 1831230. Its totient is φ = 610408.

The previous prime is 1220803. The next prime is 1220819. The reversal of 1220818 is 8180221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1096209 + 124609 = 1047^2 + 353^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (1220819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305203 + ... + 305206.

2^1220818 is an apocalyptic number.

1220818 is a deficient number, since it is larger than the sum of its proper divisors (610412).

1220818 is an equidigital number, since it uses as much as digits as its factorization.

1220818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610411.

The product of its (nonzero) digits is 256, while the sum is 22.

The square root of 1220818 is about 1104.9063308715. The cubic root of 1220818 is about 106.8768490270.

The spelling of 1220818 in words is "one million, two hundred twenty thousand, eight hundred eighteen".