7728257 has 4 divisors (see below), whose sum is σ = 7892736. Its totient is φ = 7563780.

The previous prime is 7728221. The next prime is 7728271. The reversal of 7728257 is 7528277.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7528277 = 431 ⋅17467.

It is a cyclic number.

It is not a de Polignac number, because 7728257 - 2¹⁰ = 7727233 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7728257.

It is not an unprimeable number, because it can be changed into a prime (7728757) 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, 82169 + ... + 82262.

It is an arithmetic number, because the mean of its divisors is an integer number (1973184).

Almost surely, 2^7728257 is an apocalyptic number.

It is an amenable number.

7728257 is a deficient number, since it is larger than the sum of its proper divisors (164479).

7728257 is a wasteful number, since it uses less digits than its factorization.

7728257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164478.

The product of its digits is 54880, while the sum is 38.

The square root of 7728257 is about 2779.9742804566. The cubic root of 7728257 is about 197.7093395347.

The spelling of 7728257 in words is "seven million, seven hundred twenty-eight thousand, two hundred fifty-seven".