77808891771 has 24 divisors (see below), whose sum is σ = 121360615376. Its totient is φ = 47753997120.

The previous prime is 77808891697. The next prime is 77808891791. The reversal of 77808891771 is 17719880877.

It is not a de Polignac number, because 77808891771 - 2¹⁷ = 77808760699 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 77808891699 and 77808891708.

It is not an unprimeable number, because it can be changed into a prime (77808891791) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 847825 + ... + 935106.

Almost surely, 2^77808891771 is an apocalyptic number.

77808891771 is a deficient number, since it is larger than the sum of its proper divisors (43551723605).

77808891771 is a wasteful number, since it uses less digits than its factorization.

77808891771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1783323 (or 1783320 counting only the distinct ones).

The product of its (nonzero) digits is 11063808, while the sum is 63.

The spelling of 77808891771 in words is "seventy-seven billion, eight hundred eight million, eight hundred ninety-one thousand, seven hundred seventy-one".