780656646 has 64 divisors (see below), whose sum is σ = 1994098176. Its totient is φ = 197817600.

The previous prime is 780656633. The next prime is 780656651. The reversal of 780656646 is 646656087.

It is a junction number, because it is equal to n+sod(n) for n = 780656595 and 780656604.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 1665 + ... + 39548.

It is an arithmetic number, because the mean of its divisors is an integer number (31157784).

Almost surely, 2^780656646 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 780656646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (997049088).

780656646 is an abundant number, since it is smaller than the sum of its proper divisors (1213441530).

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

780656646 is a wasteful number, since it uses less digits than its factorization.

780656646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41277.

The product of its (nonzero) digits is 1451520, while the sum is 48.

The square root of 780656646 is about 27940.2334635915. The cubic root of 780656646 is about 920.7746492243.

The spelling of 780656646 in words is "seven hundred eighty million, six hundred fifty-six thousand, six hundred forty-six".