781432280813 has 2 divisors, whose sum is σ = 781432280814. Its totient is φ = 781432280812.

The previous prime is 781432280809. The next prime is 781432280917. The reversal of 781432280813 is 318082234187.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 602141856484 + 179290424329 = 775978^2 + 423427^2 .

It is a cyclic number.

It is not a de Polignac number, because 781432280813 - 2² = 781432280809 is a prime.

It is a super-2 number, since 2×781432280813² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (781432280803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390716140406 + 390716140407.

It is an arithmetic number, because the mean of its divisors is an integer number (390716140407).

Almost surely, 2^781432280813 is an apocalyptic number.

It is an amenable number.

781432280813 is a deficient number, since it is larger than the sum of its proper divisors (1).

781432280813 is an equidigital number, since it uses as much as digits as its factorization.

781432280813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 516096, while the sum is 47.

The spelling of 781432280813 in words is "seven hundred eighty-one billion, four hundred thirty-two million, two hundred eighty thousand, eight hundred thirteen".