728775 has 36 divisors (see below), whose sum is σ = 1354080. Its totient is φ = 374400.

The previous prime is 728771. The next prime is 728809. The reversal of 728775 is 577827.

It is not a de Polignac number, because 728775 - 2² = 728771 is a prime.

It is a super-2 number, since 2×728775² = 1062226001250, which contains 22 as substring.

728775 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728771) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 9186 + ... + 9264.

2⁷²⁸⁷⁷⁵ is an apocalyptic number.

728775 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

728775 is a deficient number, since it is larger than the sum of its proper divisors (625305).

728775 is a wasteful number, since it uses less digits than its factorization.

728775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136 (or 128 counting only the distinct ones).

The product of its digits is 27440, while the sum is 36.

The square root of 728775 is about 853.6831965079. The cubic root of 728775 is about 89.9907397880.

It can be divided in two parts, 7 and 28775, that added together give a palindrome (28782).

The spelling of 728775 in words is "seven hundred twenty-eight thousand, seven hundred seventy-five".