77081206778 has 8 divisors (see below), whose sum is σ = 122423093172. Its totient is φ = 36273509056.

The previous prime is 77081206759. The next prime is 77081206781. The reversal of 77081206778 is 87760218077.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 77068977769 + 12229009 = 277613^2 + 3497^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1133547125 + ... + 1133547192.

Almost surely, 2^77081206778 is an apocalyptic number.

77081206778 is a deficient number, since it is larger than the sum of its proper divisors (45341886394).

77081206778 is a wasteful number, since it uses less digits than its factorization.

77081206778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2267094336.

The product of its (nonzero) digits is 1843968, while the sum is 53.

The spelling of 77081206778 in words is "seventy-seven billion, eighty-one million, two hundred six thousand, seven hundred seventy-eight".