1820338217 has 2 divisors, whose sum is σ = 1820338218. Its totient is φ = 1820338216.

The previous prime is 1820338193. The next prime is 1820338277. The reversal of 1820338217 is 7128330281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1809736681 + 10601536 = 42541^2 + 3256^2 .

It is a cyclic number.

It is not a de Polignac number, because 1820338217 - 2¹⁰ = 1820337193 is a prime.

It is not a weakly prime, because it can be changed into another prime (1820338277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910169108 + 910169109.

It is an arithmetic number, because the mean of its divisors is an integer number (910169109).

Almost surely, 2^1820338217 is an apocalyptic number.

It is an amenable number.

1820338217 is a deficient number, since it is larger than the sum of its proper divisors (1).

1820338217 is an equidigital number, since it uses as much as digits as its factorization.

1820338217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 1820338217 is about 42665.4217956415. The cubic root of 1820338217 is about 1221.0047749148.

Adding to 1820338217 its reverse (7128330281), we get a palindrome (8948668498).

The spelling of 1820338217 in words is "one billion, eight hundred twenty million, three hundred thirty-eight thousand, two hundred seventeen".