28297769 has 4 divisors (see below), whose sum is σ = 28310100. Its totient is φ = 28285440.

The previous prime is 28297747. The next prime is 28297777. The reversal of 28297769 is 96779282.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 96779282 = 2 ⋅48389641.

It can be written as a sum of positive squares in 2 ways, for example, as 14160169 + 14137600 = 3763^2 + 3760^2 .

It is a cyclic number.

It is not a de Polignac number, because 28297769 - 2¹² = 28293673 is a prime.

It is a super-2 number, since 2×28297769² = 1601527460754722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28297739) 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, 1592 + ... + 7689.

It is an arithmetic number, because the mean of its divisors is an integer number (7077525).

Almost surely, 2^28297769 is an apocalyptic number.

It is an amenable number.

28297769 is a deficient number, since it is larger than the sum of its proper divisors (12331).

28297769 is an equidigital number, since it uses as much as digits as its factorization.

28297769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12330.

The product of its digits is 762048, while the sum is 50.

The square root of 28297769 is about 5319.5647378334. The cubic root of 28297769 is about 304.7315347918.

The spelling of 28297769 in words is "twenty-eight million, two hundred ninety-seven thousand, seven hundred sixty-nine".