7128581 has 2 divisors, whose sum is σ = 7128582. Its totient is φ = 7128580.

The previous prime is 7128533. The next prime is 7128587. The reversal of 7128581 is 1858217.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7107556 + 21025 = 2666^2 + 145^2 .

It is an emirp because it is prime and its reverse (1858217) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7128581 - 2¹⁸ = 6866437 is a prime.

It is a super-2 number, since 2×7128581² = 101633334147122, which contains 22 as substring.

It is equal to p₄₈₄₈₁₇ and since 7128581 and 484817 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7128587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3564290 + 3564291.

It is an arithmetic number, because the mean of its divisors is an integer number (3564291).

Almost surely, 2^7128581 is an apocalyptic number.

It is an amenable number.

7128581 is a deficient number, since it is larger than the sum of its proper divisors (1).

7128581 is an equidigital number, since it uses as much as digits as its factorization.

7128581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4480, while the sum is 32.

The square root of 7128581 is about 2669.9402615040. The cubic root of 7128581 is about 192.4572885506.

The spelling of 7128581 in words is "seven million, one hundred twenty-eight thousand, five hundred eighty-one".