77555477668 has 6 divisors (see below), whose sum is σ = 135722085926. Its totient is φ = 38777738832.

The previous prime is 77555477627. The next prime is 77555477669. The reversal of 77555477668 is 86677455577.

It can be written as a sum of positive squares in only one way, i.e., 43544003584 + 34011474084 = 208672^2 + 184422^2 .

It is not an unprimeable number, because it can be changed into a prime (77555477669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9694434705 + ... + 9694434712.

Almost surely, 2^77555477668 is an apocalyptic number.

It is an amenable number.

77555477668 is a deficient number, since it is larger than the sum of its proper divisors (58166608258).

77555477668 is a wasteful number, since it uses less digits than its factorization.

77555477668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19388869421 (or 19388869419 counting only the distinct ones).

The product of its digits is 345744000, while the sum is 67.

The spelling of 77555477668 in words is "seventy-seven billion, five hundred fifty-five million, four hundred seventy-seven thousand, six hundred sixty-eight".