787878377557 has 2 divisors, whose sum is σ = 787878377558. Its totient is φ = 787878377556.

The previous prime is 787878377459. The next prime is 787878377569. The reversal of 787878377557 is 755773878787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 727388942641 + 60489434916 = 852871^2 + 245946^2 .

It is a cyclic number.

It is not a de Polignac number, because 787878377557 - 2¹¹ = 787878375509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (787878317557) 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, 393939188778 + 393939188779.

It is an arithmetic number, because the mean of its divisors is an integer number (393939188779).

Almost surely, 2^787878377557 is an apocalyptic number.

It is an amenable number.

787878377557 is a deficient number, since it is larger than the sum of its proper divisors (1).

787878377557 is an equidigital number, since it uses as much as digits as its factorization.

787878377557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4517721600, while the sum is 79.

The spelling of 787878377557 in words is "seven hundred eighty-seven billion, eight hundred seventy-eight million, three hundred seventy-seven thousand, five hundred fifty-seven".