28250081 has 4 divisors (see below), whose sum is σ = 28671792. Its totient is φ = 27828372.

The previous prime is 28250071. The next prime is 28250087. The reversal of 28250081 is 18005282.

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: 18005282 = 2 ⋅9002641.

It is a cyclic number.

It is not a de Polignac number, because 28250081 - 2¹⁸ = 27987937 is a prime.

It is a super-2 number, since 2×28250081² = 1596134153013122, which contains 22 as substring.

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 28250081.

It is not an unprimeable number, because it can be changed into a prime (28250087) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210755 + ... + 210888.

It is an arithmetic number, because the mean of its divisors is an integer number (7167948).

Almost surely, 2^28250081 is an apocalyptic number.

It is an amenable number.

28250081 is a deficient number, since it is larger than the sum of its proper divisors (421711).

28250081 is an equidigital number, since it uses as much as digits as its factorization.

28250081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421710.

The product of its (nonzero) digits is 1280, while the sum is 26.

The square root of 28250081 is about 5315.0805262009. The cubic root of 28250081 is about 304.5602585296.

The spelling of 28250081 in words is "twenty-eight million, two hundred fifty thousand, eighty-one".