28272729 has 4 divisors (see below), whose sum is σ = 37696976. Its totient is φ = 18848484.

The previous prime is 28272721. The next prime is 28272731. The reversal of 28272729 is 92727282.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 28272729 - 2³ = 28272721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28272721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4712119 + ... + 4712124.

It is an arithmetic number, because the mean of its divisors is an integer number (9424244).

Almost surely, 2^28272729 is an apocalyptic number.

It is an amenable number.

28272729 is a deficient number, since it is larger than the sum of its proper divisors (9424247).

28272729 is an equidigital number, since it uses as much as digits as its factorization.

28272729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9424246.

The product of its digits is 56448, while the sum is 39.

The square root of 28272729 is about 5317.2106409282. The cubic root of 28272729 is about 304.6416251196.

The spelling of 28272729 in words is "twenty-eight million, two hundred seventy-two thousand, seven hundred twenty-nine".