77780080 has 40 divisors (see below), whose sum is σ = 206674272. Its totient is φ = 26667264.

The previous prime is 77780057. The next prime is 77780081. The reversal of 77780080 is 8008777.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77780081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68887 + ... + 70006.

Almost surely, 2^77780080 is an apocalyptic number.

77780080 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

77780080 is an abundant number, since it is smaller than the sum of its proper divisors (128894192).

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

77780080 is a wasteful number, since it uses less digits than its factorization.

77780080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138913 (or 138907 counting only the distinct ones).

The product of its (nonzero) digits is 21952, while the sum is 37.

The square root of 77780080 is about 8819.3015596475. The cubic root of 77780080 is about 426.8639333035.

The spelling of 77780080 in words is "seventy-seven million, seven hundred eighty thousand, eighty".