775231728 has 20 divisors (see below), whose sum is σ = 2002682088. Its totient is φ = 258410560.

The previous prime is 775231727. The next prime is 775231729. The reversal of 775231728 is 827132577.

It is an interprime number because it is at equal distance from previous prime (775231727) and next prime (775231729).

It is a self number, because there is not a number n which added to its sum of digits gives 775231728.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (775231727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8075283 + ... + 8075378.

Almost surely, 2^775231728 is an apocalyptic number.

It is an amenable number.

775231728 is an abundant number, since it is smaller than the sum of its proper divisors (1227450360).

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

775231728 is a wasteful number, since it uses less digits than its factorization.

775231728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16150672 (or 16150666 counting only the distinct ones).

The product of its digits is 164640, while the sum is 42.

The square root of 775231728 is about 27842.9834608290. The cubic root of 775231728 is about 918.6368154150.

The spelling of 775231728 in words is "seven hundred seventy-five million, two hundred thirty-one thousand, seven hundred twenty-eight".