1218021 has 16 divisors (see below), whose sum is σ = 1916928. Its totient is φ = 673200.

The previous prime is 1218017. The next prime is 1218043. The reversal of 1218021 is 1208121.

It is not a de Polignac number, because 1218021 - 2² = 1218017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218121) 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 15 ways as a sum of consecutive naturals, for example, 285 + ... + 1586.

It is an arithmetic number, because the mean of its divisors is an integer number (119808).

2^1218021 is an apocalyptic number.

It is an amenable number.

1218021 is a deficient number, since it is larger than the sum of its proper divisors (698907).

1218021 is a wasteful number, since it uses less digits than its factorization.

1218021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1912.

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 1218021 is about 1103.6398869196. The cubic root of 1218021 is about 106.7951652344.

The spelling of 1218021 in words is "one million, two hundred eighteen thousand, twenty-one".