77785478548 has 6 divisors (see below), whose sum is σ = 136124587466. Its totient is φ = 38892739272.

The previous prime is 77785478543. The next prime is 77785478593. The reversal of 77785478548 is 84587458777.

It can be written as a sum of positive squares in only one way, i.e., 71487786384 + 6297692164 = 267372^2 + 79358^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77785478543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9723184815 + ... + 9723184822.

Almost surely, 2^77785478548 is an apocalyptic number.

It is an amenable number.

77785478548 is a deficient number, since it is larger than the sum of its proper divisors (58339108918).

77785478548 is a wasteful number, since it uses less digits than its factorization.

77785478548 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19446369641 (or 19446369639 counting only the distinct ones).

The product of its digits is 491724800, while the sum is 70.

The spelling of 77785478548 in words is "seventy-seven billion, seven hundred eighty-five million, four hundred seventy-eight thousand, five hundred forty-eight".