78335777781 has 8 divisors (see below), whose sum is σ = 116053004160. Its totient is φ = 52223851836.

The previous prime is 78335777743. The next prime is 78335777789. The reversal of 78335777781 is 18777753387.

It is not a de Polignac number, because 78335777781 - 2⁹ = 78335777269 is a prime.

It is a super-2 number, since 2×78335777781² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78335777789) 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, 1450662525 + ... + 1450662578.

It is an arithmetic number, because the mean of its divisors is an integer number (14506625520).

Almost surely, 2^78335777781 is an apocalyptic number.

It is an amenable number.

78335777781 is a deficient number, since it is larger than the sum of its proper divisors (37717226379).

78335777781 is a wasteful number, since it uses less digits than its factorization.

78335777781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2901325112 (or 2901325106 counting only the distinct ones).

The product of its digits is 48404160, while the sum is 63.

The spelling of 78335777781 in words is "seventy-eight billion, three hundred thirty-five million, seven hundred seventy-seven thousand, seven hundred eighty-one".