28013761 has 4 divisors (see below), whose sum is σ = 28080724. Its totient is φ = 27946800.

The previous prime is 28013759. The next prime is 28013767. The reversal of 28013761 is 16731082.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16731082 = 2 ⋅8365541.

It can be written as a sum of positive squares in 2 ways, for example, as 10112400 + 17901361 = 3180^2 + 4231^2 .

It is a cyclic number.

It is not a de Polignac number, because 28013761 - 2¹ = 28013759 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28013767) 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, 32850 + ... + 33691.

It is an arithmetic number, because the mean of its divisors is an integer number (7020181).

Almost surely, 2^28013761 is an apocalyptic number.

It is an amenable number.

28013761 is a deficient number, since it is larger than the sum of its proper divisors (66963).

28013761 is an equidigital number, since it uses as much as digits as its factorization.

28013761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66962.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 28013761 is about 5292.8027546849. The cubic root of 28013761 is about 303.7086348747.

It can be divided in two parts, 280 and 13761, that added together give a palindrome (14041).

The spelling of 28013761 in words is "twenty-eight million, thirteen thousand, seven hundred sixty-one".