77561917886 has 16 divisors (see below), whose sum is σ = 123237049536. Its totient is φ = 36484770816.

The previous prime is 77561917861. The next prime is 77561917907. The reversal of 77561917886 is 68871916577.

It is a super-2 number, since 2×77561917886² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 382931 + ... + 549326.

It is an arithmetic number, because the mean of its divisors is an integer number (7702315596).

Almost surely, 2^77561917886 is an apocalyptic number.

77561917886 is a deficient number, since it is larger than the sum of its proper divisors (45675131650).

77561917886 is a wasteful number, since it uses less digits than its factorization.

77561917886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934723.

The product of its digits is 35562240, while the sum is 65.

The spelling of 77561917886 in words is "seventy-seven billion, five hundred sixty-one million, nine hundred seventeen thousand, eight hundred eighty-six".