775777728 has 336 divisors, whose sum is σ = 2515258368. Its totient is φ = 208896000.

The previous prime is 775777669. The next prime is 775777729. The reversal of 775777728 is 827777577.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (775777729) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 18921388 + ... + 18921428.

It is an arithmetic number, because the mean of its divisors is an integer number (7485888).

Almost surely, 2^775777728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 775777728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1257629184).

775777728 is an abundant number, since it is smaller than the sum of its proper divisors (1739480640).

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

775777728 is a wasteful number, since it uses less digits than its factorization.

775777728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132 (or 105 counting only the distinct ones).

The product of its digits is 9411920, while the sum is 57.

The square root of 775777728 is about 27852.7867187468. The cubic root of 775777728 is about 918.8524318021.

The spelling of 775777728 in words is "seven hundred seventy-five million, seven hundred seventy-seven thousand, seven hundred twenty-eight".