780400355557 has 2 divisors, whose sum is σ = 780400355558. Its totient is φ = 780400355556.

The previous prime is 780400355549. The next prime is 780400355621. The reversal of 780400355557 is 755553004087.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 722183834596 + 58216520961 = 849814^2 + 241281^2 .

It is a cyclic number.

It is not a de Polignac number, because 780400355557 - 2³ = 780400355549 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 780400355557.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (780400455557) 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, 390200177778 + 390200177779.

It is an arithmetic number, because the mean of its divisors is an integer number (390200177779).

Almost surely, 2^780400355557 is an apocalyptic number.

It is an amenable number.

780400355557 is a deficient number, since it is larger than the sum of its proper divisors (1).

780400355557 is an equidigital number, since it uses as much as digits as its factorization.

780400355557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2940000, while the sum is 49.

The spelling of 780400355557 in words is "seven hundred eighty billion, four hundred million, three hundred fifty-five thousand, five hundred fifty-seven".