7971257 has 4 divisors (see below), whose sum is σ = 9110016. Its totient is φ = 6832500.

The previous prime is 7971251. The next prime is 7971263. The reversal of 7971257 is 7521797.

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: 7521797 = 547 ⋅13751.

It is an interprime number because it is at equal distance from previous prime (7971251) and next prime (7971263).

It is a cyclic number.

It is not a de Polignac number, because 7971257 - 2¹⁸ = 7709113 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 7971257.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7971251) 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 in 3 ways as a sum of consecutive naturals, for example, 569369 + ... + 569382.

It is an arithmetic number, because the mean of its divisors is an integer number (2277504).

Almost surely, 2^7971257 is an apocalyptic number.

It is an amenable number.

7971257 is a deficient number, since it is larger than the sum of its proper divisors (1138759).

7971257 is a wasteful number, since it uses less digits than its factorization.

7971257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1138758.

The product of its digits is 30870, while the sum is 38.

The square root of 7971257 is about 2823.3414600434. The cubic root of 7971257 is about 199.7601875649.

It can be divided in two parts, 7971 and 257, that added together give a palindrome (8228).

The spelling of 7971257 in words is "seven million, nine hundred seventy-one thousand, two hundred fifty-seven".