7928257 has 2 divisors, whose sum is σ = 7928258. Its totient is φ = 7928256.

The previous prime is 7928201. The next prime is 7928267. The reversal of 7928257 is 7528297.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5740816 + 2187441 = 2396^2 + 1479^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7928257 is a prime.

7928257 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (7928267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3964128 + 3964129.

It is an arithmetic number, because the mean of its divisors is an integer number (3964129).

Almost surely, 2^7928257 is an apocalyptic number.

It is an amenable number.

7928257 is a deficient number, since it is larger than the sum of its proper divisors (1).

7928257 is an equidigital number, since it uses as much as digits as its factorization.

7928257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 70560, while the sum is 40.

The square root of 7928257 is about 2815.7160723340. The cubic root of 7928257 is about 199.4003455362.

Adding to 7928257 its sum of digits (40), we get a palindrome (7928297).

The spelling of 7928257 in words is "seven million, nine hundred twenty-eight thousand, two hundred fifty-seven".