8161777768 has 32 divisors (see below), whose sum is σ = 15484689000. Its totient is φ = 4032808192.

The previous prime is 8161777759. The next prime is 8161777787. The reversal of 8161777768 is 8677771618.

It can be written as a sum of positive squares in 4 ways, for example, as 6773619204 + 1388158564 = 82302^2 + 37258^2 .

It is a super-2 number, since 2×8161777768² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 217446 + ... + 252202.

Almost surely, 2^8161777768 is an apocalyptic number.

It is an amenable number.

8161777768 is a deficient number, since it is larger than the sum of its proper divisors (7322911232).

8161777768 is a wasteful number, since it uses less digits than its factorization.

8161777768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35109 (or 35105 counting only the distinct ones).

The product of its digits is 5531904, while the sum is 58.

The square root of 8161777768 is about 90342.5579004712. The cubic root of 8161777768 is about 2013.3916128864.

The spelling of 8161777768 in words is "eight billion, one hundred sixty-one million, seven hundred seventy-seven thousand, seven hundred sixty-eight".