7785720013 has 2 divisors, whose sum is σ = 7785720014. Its totient is φ = 7785720012.

The previous prime is 7785719989. The next prime is 7785720023. The reversal of 7785720013 is 3100275877.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7042230724 + 743489289 = 83918^2 + 27267^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7785720013 is a prime.

It is a super-2 number, since 2×7785720013² (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 (7785720023) 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 as a sum of consecutive naturals, namely, 3892860006 + 3892860007.

It is an arithmetic number, because the mean of its divisors is an integer number (3892860007).

Almost surely, 2^7785720013 is an apocalyptic number.

It is an amenable number.

7785720013 is a deficient number, since it is larger than the sum of its proper divisors (1).

7785720013 is an equidigital number, since it uses as much as digits as its factorization.

7785720013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 82320, while the sum is 40.

The square root of 7785720013 is about 88236.7271208537. The cubic root of 7785720013 is about 1981.9814885400.

The spelling of 7785720013 in words is "seven billion, seven hundred eighty-five million, seven hundred twenty thousand, thirteen".