1118821 has 16 divisors (see below), whose sum is σ = 1340928. Its totient is φ = 921600.

The previous prime is 1118809. The next prime is 1118827. The reversal of 1118821 is 1288111.

It is a 6-Lehmer number, since φ(1118821) divides (1118821-1)⁶.

It is a cyclic number.

It is not a de Polignac number, because 1118821 - 2⁹ = 1118309 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1118792 and 1118801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1118827) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5701 + ... + 5893.

It is an arithmetic number, because the mean of its divisors is an integer number (83808).

2^1118821 is an apocalyptic number.

1118821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1118821 is a deficient number, since it is larger than the sum of its proper divisors (222107).

1118821 is a wasteful number, since it uses less digits than its factorization.

1118821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252.

The product of its digits is 128, while the sum is 22.

The square root of 1118821 is about 1057.7433526144. The cubic root of 1118821 is about 103.8134290611.

The spelling of 1118821 in words is "one million, one hundred eighteen thousand, eight hundred twenty-one".