77701890778 has 4 divisors (see below), whose sum is σ = 116552836170. Its totient is φ = 38850945388.

The previous prime is 77701890733. The next prime is 77701890779. The reversal of 77701890778 is 87709810777.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 48209667489 + 29492223289 = 219567^2 + 171733^2 .

It is not an unprimeable number, because it can be changed into a prime (77701890779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19425472693 + ... + 19425472696.

Almost surely, 2^77701890778 is an apocalyptic number.

77701890778 is a deficient number, since it is larger than the sum of its proper divisors (38850945392).

77701890778 is a wasteful number, since it uses less digits than its factorization.

77701890778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38850945391.

The product of its (nonzero) digits is 9680832, while the sum is 61.

The spelling of 77701890778 in words is "seventy-seven billion, seven hundred one million, eight hundred ninety thousand, seven hundred seventy-eight".