1780320728 has 8 divisors (see below), whose sum is σ = 3338101380. Its totient is φ = 890160360.

The previous prime is 1780320713. The next prime is 1780320779. The reversal of 1780320728 is 8270230871.

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 1780320691 and 1780320700.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111270038 + ... + 111270053.

Almost surely, 2^1780320728 is an apocalyptic number.

It is an amenable number.

1780320728 is a deficient number, since it is larger than the sum of its proper divisors (1557780652).

1780320728 is a wasteful number, since it uses less digits than its factorization.

1780320728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222540097 (or 222540093 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 38.

The square root of 1780320728 is about 42193.8470395862. The cubic root of 1780320728 is about 1211.9910592710.

The spelling of 1780320728 in words is "one billion, seven hundred eighty million, three hundred twenty thousand, seven hundred twenty-eight".