28681777 has 4 divisors (see below), whose sum is σ = 28744996. Its totient is φ = 28618560.

The previous prime is 28681753. The next prime is 28681781. The reversal of 28681777 is 77718682.

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 13905441 + 14776336 = 3729^2 + 3844^2 .

It is a cyclic number.

It is not a de Polignac number, because 28681777 - 2⁷ = 28681649 is a prime.

It is a super-3 number, since 3×28681777³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28681717) 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, 30924 + ... + 31837.

It is an arithmetic number, because the mean of its divisors is an integer number (7186249).

Almost surely, 2^28681777 is an apocalyptic number.

It is an amenable number.

28681777 is a deficient number, since it is larger than the sum of its proper divisors (63219).

28681777 is an equidigital number, since it uses as much as digits as its factorization.

28681777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63218.

The product of its digits is 263424, while the sum is 46.

The square root of 28681777 is about 5355.5370412313. The cubic root of 28681777 is about 306.1037745909.

The spelling of 28681777 in words is "twenty-eight million, six hundred eighty-one thousand, seven hundred seventy-seven".