77700007778 has 8 divisors (see below), whose sum is σ = 116552257068. Its totient is φ = 38849255424.

The previous prime is 77700007771. The next prime is 77700007793. The reversal of 77700007778 is 87770000777.

It can be written as a sum of positive squares in 2 ways, for example, as 70706532649 + 6993475129 = 265907^2 + 83627^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (77700007771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 233951 + ... + 458402.

Almost surely, 2^77700007778 is an apocalyptic number.

77700007778 is a deficient number, since it is larger than the sum of its proper divisors (38852249290).

77700007778 is a wasteful number, since it uses less digits than its factorization.

77700007778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 748468.

The product of its (nonzero) digits is 941192, while the sum is 50.

The spelling of 77700007778 in words is "seventy-seven billion, seven hundred million, seven thousand, seven hundred seventy-eight".