765505728 has 280 divisors, whose sum is σ = 2517975152. Its totient is φ = 228427776.

The previous prime is 765505681. The next prime is 765505729. The reversal of 765505728 is 827505567.

765505728 is a `hidden beast` number, since 76 + 5 + 5 + 0 + 572 + 8 = 666.

It is not an unprimeable number, because it can be changed into a prime (765505729) 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 39 ways as a sum of consecutive naturals, for example, 2493351 + ... + 2493657.

Almost surely, 2^765505728 is an apocalyptic number.

765505728 is a gapful number since it is divisible by the number (78) 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 765505728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1258987576).

765505728 is an abundant number, since it is smaller than the sum of its proper divisors (1752469424).

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

765505728 is a wasteful number, since it uses less digits than its factorization.

765505728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381 (or 362 counting only the distinct ones).

The product of its (nonzero) digits is 588000, while the sum is 45.

The square root of 765505728 is about 27667.7741786361. The cubic root of 765505728 is about 914.7789199817.

The spelling of 765505728 in words is "seven hundred sixty-five million, five hundred five thousand, seven hundred twenty-eight".