7820900509 has 2 divisors, whose sum is σ = 7820900510. Its totient is φ = 7820900508.

The previous prime is 7820900489. The next prime is 7820900573. The reversal of 7820900509 is 9050090287.

7820900509 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6336956025 + 1483944484 = 79605^2 + 38522^2 .

It is a cyclic number.

It is not a de Polignac number, because 7820900509 - 2¹⁵ = 7820867741 is a prime.

It is a super-2 number, since 2×7820900509² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7820900579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3910450254 + 3910450255.

It is an arithmetic number, because the mean of its divisors is an integer number (3910450255).

Almost surely, 2^7820900509 is an apocalyptic number.

It is an amenable number.

7820900509 is a deficient number, since it is larger than the sum of its proper divisors (1).

7820900509 is an equidigital number, since it uses as much as digits as its factorization.

7820900509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 7820900509 is about 88435.8553359439. The cubic root of 7820900509 is about 1984.9622589673.

The spelling of 7820900509 in words is "seven billion, eight hundred twenty million, nine hundred thousand, five hundred nine".