7809781493 has 2 divisors, whose sum is σ = 7809781494. Its totient is φ = 7809781492.

The previous prime is 7809781471. The next prime is 7809781513. The reversal of 7809781493 is 3941879087.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7659400324 + 150381169 = 87518^2 + 12263^2 .

It is a cyclic number.

It is not a de Polignac number, because 7809781493 - 2⁶ = 7809781429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7809781433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3904890746 + 3904890747.

It is an arithmetic number, because the mean of its divisors is an integer number (3904890747).

Almost surely, 2^7809781493 is an apocalyptic number.

It is an amenable number.

7809781493 is a deficient number, since it is larger than the sum of its proper divisors (1).

7809781493 is an equidigital number, since it uses as much as digits as its factorization.

7809781493 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3048192, while the sum is 56.

The square root of 7809781493 is about 88372.9681124268. The cubic root of 7809781493 is about 1984.0211356800.

The spelling of 7809781493 in words is "seven billion, eight hundred nine million, seven hundred eighty-one thousand, four hundred ninety-three".