28878749 has 2 divisors, whose sum is σ = 28878750. Its totient is φ = 28878748.

The previous prime is 28878683. The next prime is 28878761. The reversal of 28878749 is 94787882.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27227524 + 1651225 = 5218^2 + 1285^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28878749 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28878749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28878769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14439374 + 14439375.

It is an arithmetic number, because the mean of its divisors is an integer number (14439375).

Almost surely, 2^28878749 is an apocalyptic number.

It is an amenable number.

28878749 is a deficient number, since it is larger than the sum of its proper divisors (1).

28878749 is an equidigital number, since it uses as much as digits as its factorization.

28878749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1806336, while the sum is 53.

The square root of 28878749 is about 5373.8951422595. The cubic root of 28878749 is about 306.8028988029.

The spelling of 28878749 in words is "twenty-eight million, eight hundred seventy-eight thousand, seven hundred forty-nine".