7128257 has 4 divisors (see below), whose sum is σ = 7175616. Its totient is φ = 7080900.

The previous prime is 7128227. The next prime is 7128259. The reversal of 7128257 is 7528217.

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.

It is a cyclic number.

It is not a de Polignac number, because 7128257 - 2⁶ = 7128193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7128259) 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, 23453 + ... + 23754.

It is an arithmetic number, because the mean of its divisors is an integer number (1793904).

Almost surely, 2^7128257 is an apocalyptic number.

It is an amenable number.

7128257 is a deficient number, since it is larger than the sum of its proper divisors (47359).

7128257 is a wasteful number, since it uses less digits than its factorization.

7128257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47358.

The product of its digits is 7840, while the sum is 32.

The square root of 7128257 is about 2669.8795852997. The cubic root of 7128257 is about 192.4543727246.

The spelling of 7128257 in words is "seven million, one hundred twenty-eight thousand, two hundred fifty-seven".