28727777 has 16 divisors (see below), whose sum is σ = 32257680. Its totient is φ = 25401600.

The previous prime is 28727747. The next prime is 28727779. The reversal of 28727777 is 77772782.

It can be written as a sum of positive squares in 8 ways, for example, as 17106496 + 11621281 = 4136^2 + 3409^2 .

It is a cyclic number.

It is not a de Polignac number, because 28727777 - 2¹⁴ = 28711393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28727779) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68027 + ... + 68447.

It is an arithmetic number, because the mean of its divisors is an integer number (2016105).

Almost surely, 2^28727777 is an apocalyptic number.

It is an amenable number.

28727777 is a deficient number, since it is larger than the sum of its proper divisors (3529903).

28727777 is a wasteful number, since it uses less digits than its factorization.

28727777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644.

The product of its digits is 537824, while the sum is 47.

The square root of 28727777 is about 5359.8299413321. The cubic root of 28727777 is about 306.2673308532.

The spelling of 28727777 in words is "twenty-eight million, seven hundred twenty-seven thousand, seven hundred seventy-seven".