28250581 has 2 divisors, whose sum is σ = 28250582. Its totient is φ = 28250580.

The previous prime is 28250569. The next prime is 28250591. The reversal of 28250581 is 18505282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26471025 + 1779556 = 5145^2 + 1334^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28250581 is a prime.

It is a super-2 number, since 2×28250581² = 1596190653675122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28250561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14125290 + 14125291.

It is an arithmetic number, because the mean of its divisors is an integer number (14125291).

Almost surely, 2^28250581 is an apocalyptic number.

It is an amenable number.

28250581 is a deficient number, since it is larger than the sum of its proper divisors (1).

28250581 is an equidigital number, since it uses as much as digits as its factorization.

28250581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6400, while the sum is 31.

The square root of 28250581 is about 5315.1275619688. The cubic root of 28250581 is about 304.5620553295.

The spelling of 28250581 in words is "twenty-eight million, two hundred fifty thousand, five hundred eighty-one".