780780261556 has 6 divisors (see below), whose sum is σ = 1366365457730. Its totient is φ = 390390130776.

The previous prime is 780780261553. The next prime is 780780261557. The reversal of 780780261556 is 655162087087.

It can be written as a sum of positive squares in only one way, i.e., 449101022500 + 331679239056 = 670150^2 + 575916^2 .

It is a super-2 number, since 2×780780261556² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 780780261497 and 780780261506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (780780261553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97597532691 + ... + 97597532698.

Almost surely, 2^780780261556 is an apocalyptic number.

It is an amenable number.

780780261556 is a deficient number, since it is larger than the sum of its proper divisors (585585196174).

780780261556 is a wasteful number, since it uses less digits than its factorization.

780780261556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195195065393 (or 195195065391 counting only the distinct ones).

The product of its (nonzero) digits is 5644800, while the sum is 55.

The spelling of 780780261556 in words is "seven hundred eighty billion, seven hundred eighty million, two hundred sixty-one thousand, five hundred fifty-six".