77880780 has 72 divisors (see below), whose sum is σ = 239514912. Its totient is φ = 20480256.

The previous prime is 77880769. The next prime is 77880799. The reversal of 77880780 is 8708877.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10177 + ... + 16103.

It is an arithmetic number, because the mean of its divisors is an integer number (3326596).

Almost surely, 2^77880780 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77880780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119757456).

77880780 is an abundant number, since it is smaller than the sum of its proper divisors (161634132).

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

77880780 is a wasteful number, since it uses less digits than its factorization.

77880780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6015 (or 6010 counting only the distinct ones).

The product of its (nonzero) digits is 175616, while the sum is 45.

The square root of 77880780 is about 8825.0087818653. The cubic root of 77880780 is about 427.0480706850.

The spelling of 77880780 in words is "seventy-seven million, eight hundred eighty thousand, seven hundred eighty".