28639347 has 32 divisors (see below), whose sum is σ = 44029440. Its totient is φ = 16389120.

The previous prime is 28639337. The next prime is 28639363. The reversal of 28639347 is 74393682.

It is not a de Polignac number, because 28639347 - 2⁶ = 28639283 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28639299 and 28639308.

It is not an unprimeable number, because it can be changed into a prime (28639337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 73429 + ... + 73817.

It is an arithmetic number, because the mean of its divisors is an integer number (1375920).

Almost surely, 2^28639347 is an apocalyptic number.

28639347 is a deficient number, since it is larger than the sum of its proper divisors (15390093).

28639347 is a wasteful number, since it uses less digits than its factorization.

28639347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 523.

The product of its digits is 217728, while the sum is 42.

The square root of 28639347 is about 5351.5742543667. The cubic root of 28639347 is about 305.9527566007.

The spelling of 28639347 in words is "twenty-eight million, six hundred thirty-nine thousand, three hundred forty-seven".