28718649 has 6 divisors (see below), whose sum is σ = 41482506. Its totient is φ = 19145760.

The previous prime is 28718647. The next prime is 28718687. The reversal of 28718649 is 94681782.

It can be written as a sum of positive squares in only one way, i.e., 20766249 + 7952400 = 4557^2 + 2820^2 .

It is not a de Polignac number, because 28718649 - 2¹ = 28718647 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28718647) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1595472 + ... + 1595489.

It is an arithmetic number, because the mean of its divisors is an integer number (6913751).

Almost surely, 2^28718649 is an apocalyptic number.

It is an amenable number.

28718649 is a deficient number, since it is larger than the sum of its proper divisors (12763857).

28718649 is a wasteful number, since it uses less digits than its factorization.

28718649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3190967 (or 3190964 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 28718649 is about 5358.9783541268. The cubic root of 28718649 is about 306.2348894946.

The spelling of 28718649 in words is "twenty-eight million, seven hundred eighteen thousand, six hundred forty-nine".