781125062813 has 4 divisors (see below), whose sum is σ = 788858974428. Its totient is φ = 773391151200.

The previous prime is 781125062807. The next prime is 781125062821. The reversal of 781125062813 is 318260521187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 318260521187 = 7 ⋅45465788741.

It can be written as a sum of positive squares in 2 ways, for example, as 631964581444 + 149160481369 = 794962^2 + 386213^2 .

It is a cyclic number.

It is not a de Polignac number, because 781125062813 - 2⁶ = 781125062749 is a prime.

It is a super-2 number, since 2×781125062813² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781125062713) 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 in 3 ways as a sum of consecutive naturals, for example, 3866955656 + ... + 3866955857.

It is an arithmetic number, because the mean of its divisors is an integer number (197214743607).

Almost surely, 2^781125062813 is an apocalyptic number.

It is an amenable number.

781125062813 is a deficient number, since it is larger than the sum of its proper divisors (7733911615).

781125062813 is a wasteful number, since it uses less digits than its factorization.

781125062813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7733911614.

The product of its (nonzero) digits is 161280, while the sum is 44.

The spelling of 781125062813 in words is "seven hundred eighty-one billion, one hundred twenty-five million, sixty-two thousand, eight hundred thirteen".