77776780 has 24 divisors (see below), whose sum is σ = 163563120. Its totient is φ = 31066560.

The previous prime is 77776771. The next prime is 77776781. The reversal of 77776780 is 8767777.

It is not an unprimeable number, because it can be changed into a prime (77776781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14235 + ... + 18925.

It is an arithmetic number, because the mean of its divisors is an integer number (6815130).

Almost surely, 2^77776780 is an apocalyptic number.

It is an amenable number.

77776780 is an abundant number, since it is smaller than the sum of its proper divisors (85786340).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77776780 is a wasteful number, since it uses less digits than its factorization.

77776780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5529 (or 5527 counting only the distinct ones).

The product of its (nonzero) digits is 806736, while the sum is 49.

The square root of 77776780 is about 8819.1144680177. The cubic root of 77776780 is about 426.8578963212.

The spelling of 77776780 in words is "seventy-seven million, seven hundred seventy-six thousand, seven hundred eighty".