1820117 has 4 divisors (see below), whose sum is σ = 1960140. Its totient is φ = 1680096.

The previous prime is 1820111. The next prime is 1820123. The reversal of 1820117 is 7110281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7110281 = 1481 ⋅4801.

It is an interprime number because it is at equal distance from previous prime (1820111) and next prime (1820123).

It can be written as a sum of positive squares in 2 ways, for example, as 579121 + 1240996 = 761^2 + 1114^2 .

It is a cyclic number.

It is not a de Polignac number, because 1820117 - 2¹⁶ = 1754581 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69992 + ... + 70017.

It is an arithmetic number, because the mean of its divisors is an integer number (490035).

2^1820117 is an apocalyptic number.

It is an amenable number.

1820117 is a deficient number, since it is larger than the sum of its proper divisors (140023).

1820117 is a wasteful number, since it uses less digits than its factorization.

1820117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140022.

The product of its (nonzero) digits is 112, while the sum is 20.

The square root of 1820117 is about 1349.1171187113. The cubic root of 1820117 is about 122.0955311954.

Adding to 1820117 its reverse (7110281), we get a palindrome (8930398).

The spelling of 1820117 in words is "one million, eight hundred twenty thousand, one hundred seventeen".