77653809549 has 6 divisors (see below), whose sum is σ = 112166613806. Its totient is φ = 51769206360.

The previous prime is 77653809529. The next prime is 77653809551. The reversal of 77653809549 is 94590835677.

77653809549 is a `hidden beast` number, since 7 + 7 + 6 + 5 + 3 + 80 + 9 + 549 = 666.

It can be written as a sum of positive squares in only one way, i.e., 75795596100 + 1858213449 = 275310^2 + 43107^2 .

It is not a de Polignac number, because 77653809549 - 2⁷ = 77653809421 is a prime.

It is a super-2 number, since 2×77653809549² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77653809529) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4314100522 + ... + 4314100539.

Almost surely, 2^77653809549 is an apocalyptic number.

It is an amenable number.

77653809549 is a deficient number, since it is larger than the sum of its proper divisors (34512804257).

77653809549 is a wasteful number, since it uses less digits than its factorization.

77653809549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8628201067 (or 8628201064 counting only the distinct ones).

The product of its (nonzero) digits is 57153600, while the sum is 63.

The spelling of 77653809549 in words is "seventy-seven billion, six hundred fifty-three million, eight hundred nine thousand, five hundred forty-nine".