28694081 has 4 divisors (see below), whose sum is σ = 30901332. Its totient is φ = 26486832.

The previous prime is 28694053. The next prime is 28694117. The reversal of 28694081 is 18049682.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15335056 + 13359025 = 3916^2 + 3655^2 .

It is a cyclic number.

It is not a de Polignac number, because 28694081 - 2¹⁸ = 28431937 is a prime.

It is a super-2 number, since 2×28694081² = 1646700568869122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28694051) 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, 1103606 + ... + 1103631.

It is an arithmetic number, because the mean of its divisors is an integer number (7725333).

Almost surely, 2^28694081 is an apocalyptic number.

It is an amenable number.

28694081 is a deficient number, since it is larger than the sum of its proper divisors (2207251).

28694081 is a wasteful number, since it uses less digits than its factorization.

28694081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2207250.

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 28694081 is about 5356.6856357266. The cubic root of 28694081 is about 306.1475394573.

The spelling of 28694081 in words is "twenty-eight million, six hundred ninety-four thousand, eighty-one".