28295681 has 12 divisors (see below), whose sum is σ = 29961540. Its totient is φ = 26716800.

The previous prime is 28295671. The next prime is 28295689. The reversal of 28295681 is 18659282.

It can be written as a sum of positive squares in 2 ways, for example, as 14753281 + 13542400 = 3841^2 + 3680^2 .

It is not a de Polignac number, because 28295681 - 2¹⁰ = 28294657 is a prime.

It is a super-2 number, since 2×28295681² = 1601291126507522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28295689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 46781 + ... + 47381.

It is an arithmetic number, because the mean of its divisors is an integer number (2496795).

Almost surely, 2^28295681 is an apocalyptic number.

It is an amenable number.

28295681 is a deficient number, since it is larger than the sum of its proper divisors (1665859).

28295681 is an equidigital number, since it uses as much as digits as its factorization.

28295681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 736 (or 713 counting only the distinct ones).

The product of its digits is 69120, while the sum is 41.

The square root of 28295681 is about 5319.3684775545. The cubic root of 28295681 is about 304.7240395591.

The spelling of 28295681 in words is "twenty-eight million, two hundred ninety-five thousand, six hundred eighty-one".