780655680 has 168 divisors, whose sum is σ = 3068799552. Its totient is φ = 178430976.

The previous prime is 780655651. The next prime is 780655697. The reversal of 780655680 is 86556087.

780655680 is a `hidden beast` number, since 7 + 80 + 6 + 5 + 568 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (168).

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 799 + ... + 39521.

It is an arithmetic number, because the mean of its divisors is an integer number (18266664).

Almost surely, 2^780655680 is an apocalyptic number.

780655680 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 780655680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1534399776).

780655680 is an abundant number, since it is smaller than the sum of its proper divisors (2288143872).

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

780655680 is a wasteful number, since it uses less digits than its factorization.

780655680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38753 (or 38740 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The square root of 780655680 is about 27940.2161766870. The cubic root of 780655680 is about 920.7742694292.

The spelling of 780655680 in words is "seven hundred eighty million, six hundred fifty-five thousand, six hundred eighty".