7728397 has 2 divisors, whose sum is σ = 7728398. Its totient is φ = 7728396.

The previous prime is 7728389. The next prime is 7728401. The reversal of 7728397 is 7938277.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7557001 + 171396 = 2749^2 + 414^2 .

It is a cyclic number.

It is not a de Polignac number, because 7728397 - 2³ = 7728389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7728317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3864198 + 3864199.

It is an arithmetic number, because the mean of its divisors is an integer number (3864199).

Almost surely, 2^7728397 is an apocalyptic number.

It is an amenable number.

7728397 is a deficient number, since it is larger than the sum of its proper divisors (1).

7728397 is an equidigital number, since it uses as much as digits as its factorization.

7728397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 148176, while the sum is 43.

The square root of 7728397 is about 2779.9994604316. Note that the first 3 decimals coincide. The cubic root of 7728397 is about 197.7105333848.

The spelling of 7728397 in words is "seven million, seven hundred twenty-eight thousand, three hundred ninety-seven".