28628399 has 4 divisors (see below), whose sum is σ = 29873136. Its totient is φ = 27383664.

The previous prime is 28628389. The next prime is 28628419. The reversal of 28628399 is 99382682.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28628399 - 2⁸ = 28628143 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28628359) 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, 622334 + ... + 622379.

It is an arithmetic number, because the mean of its divisors is an integer number (7468284).

Almost surely, 2^28628399 is an apocalyptic number.

28628399 is a deficient number, since it is larger than the sum of its proper divisors (1244737).

28628399 is a wasteful number, since it uses less digits than its factorization.

28628399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1244736.

The product of its digits is 373248, while the sum is 47.

The square root of 28628399 is about 5350.5512800084. The cubic root of 28628399 is about 305.9137659807.

The spelling of 28628399 in words is "twenty-eight million, six hundred twenty-eight thousand, three hundred ninety-nine".