28061681 has 2 divisors, whose sum is σ = 28061682. Its totient is φ = 28061680.

The previous prime is 28061659. The next prime is 28061717. The reversal of 28061681 is 18616082.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14371681 + 13690000 = 3791^2 + 3700^2 .

It is a cyclic number.

It is not a de Polignac number, because 28061681 - 2¹⁰ = 28060657 is a prime.

It is a super-3 number, since 3×28061681³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28061881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14030840 + 14030841.

It is an arithmetic number, because the mean of its divisors is an integer number (14030841).

Almost surely, 2^28061681 is an apocalyptic number.

It is an amenable number.

28061681 is a deficient number, since it is larger than the sum of its proper divisors (1).

28061681 is an equidigital number, since it uses as much as digits as its factorization.

28061681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 28061681 is about 5297.3277225409. The cubic root of 28061681 is about 303.8817096621.

The spelling of 28061681 in words is "twenty-eight million, sixty-one thousand, six hundred eighty-one".