781660813117 has 8 divisors (see below), whose sum is σ = 793066006080. Its totient is φ = 770266617120.

The previous prime is 781660813111. The next prime is 781660813133. The reversal of 781660813117 is 711318066187.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-781660813117 is a prime.

It is a super-2 number, since 2×781660813117² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781660813111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2605992 + ... + 2890417.

It is an arithmetic number, because the mean of its divisors is an integer number (99133250760).

Almost surely, 2^781660813117 is an apocalyptic number.

It is an amenable number.

781660813117 is a deficient number, since it is larger than the sum of its proper divisors (11405192963).

781660813117 is a wasteful number, since it uses less digits than its factorization.

781660813117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5498483.

The product of its (nonzero) digits is 338688, while the sum is 49.

The spelling of 781660813117 in words is "seven hundred eighty-one billion, six hundred sixty million, eight hundred thirteen thousand, one hundred seventeen".