28617749 has 4 divisors (see below), whose sum is σ = 30301164. Its totient is φ = 26934336.

The previous prime is 28617733. The next prime is 28617763. The reversal of 28617749 is 94771682.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94771682 = 2 ⋅47385841.

It can be written as a sum of positive squares in 2 ways, for example, as 24186724 + 4431025 = 4918^2 + 2105^2 .

It is a cyclic number.

It is not a de Polignac number, because 28617749 - 2⁴ = 28617733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28617709) 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, 841682 + ... + 841715.

It is an arithmetic number, because the mean of its divisors is an integer number (7575291).

Almost surely, 2^28617749 is an apocalyptic number.

It is an amenable number.

28617749 is a deficient number, since it is larger than the sum of its proper divisors (1683415).

28617749 is a wasteful number, since it uses less digits than its factorization.

28617749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1683414.

The product of its digits is 169344, while the sum is 44.

The square root of 28617749 is about 5349.5559628814. Note that the first 3 decimals coincide. The cubic root of 28617749 is about 305.8758271297.

The spelling of 28617749 in words is "twenty-eight million, six hundred seventeen thousand, seven hundred forty-nine".