28293649 has 4 divisors (see below), whose sum is σ = 28983780. Its totient is φ = 27603520.

The previous prime is 28293619. The next prime is 28293653. The reversal of 28293649 is 94639282.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94639282 = 2 ⋅47319641.

It can be written as a sum of positive squares in 2 ways, for example, as 12730624 + 15563025 = 3568^2 + 3945^2 .

It is a cyclic number.

It is not a de Polignac number, because 28293649 - 2⁷ = 28293521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28293619) 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, 345004 + ... + 345085.

It is an arithmetic number, because the mean of its divisors is an integer number (7245945).

Almost surely, 2^28293649 is an apocalyptic number.

It is an amenable number.

28293649 is a deficient number, since it is larger than the sum of its proper divisors (690131).

28293649 is an equidigital number, since it uses as much as digits as its factorization.

28293649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 690130.

The product of its digits is 186624, while the sum is 43.

The square root of 28293649 is about 5319.1774740086. The cubic root of 28293649 is about 304.7167449939.

The spelling of 28293649 in words is "twenty-eight million, two hundred ninety-three thousand, six hundred forty-nine".