77550405578 has 4 divisors (see below), whose sum is σ = 116325608370. Its totient is φ = 38775202788.

The previous prime is 77550405523. The next prime is 77550405601. The reversal of 77550405578 is 87550405577.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87550405577 = 19 ⋅4607916083.

It can be written as a sum of positive squares in only one way, i.e., 73155643729 + 4394761849 = 270473^2 + 66293^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19387601393 + ... + 19387601396.

Almost surely, 2^77550405578 is an apocalyptic number.

77550405578 is a deficient number, since it is larger than the sum of its proper divisors (38775202792).

77550405578 is a wasteful number, since it uses less digits than its factorization.

77550405578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38775202791.

The product of its (nonzero) digits is 6860000, while the sum is 53.

Subtracting 77550405578 from its reverse (87550405577), we obtain a palindrome (9999999999).

The spelling of 77550405578 in words is "seventy-seven billion, five hundred fifty million, four hundred five thousand, five hundred seventy-eight".