28820638 has 32 divisors (see below), whose sum is σ = 55646208. Its totient is φ = 10864800.

The previous prime is 28820629. The next prime is 28820639. The reversal of 28820638 is 83602882.

It is a junction number, because it is equal to n+sod(n) for n = 28820597 and 28820606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28820639) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1756 + ... + 7792.

It is an arithmetic number, because the mean of its divisors is an integer number (1738944).

Almost surely, 2^28820638 is an apocalyptic number.

28820638 is a deficient number, since it is larger than the sum of its proper divisors (26825570).

28820638 is a wasteful number, since it uses less digits than its factorization.

28820638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6088.

The product of its (nonzero) digits is 36864, while the sum is 37.

The square root of 28820638 is about 5368.4856337705. The cubic root of 28820638 is about 306.5969735032.

The spelling of 28820638 in words is "twenty-eight million, eight hundred twenty thousand, six hundred thirty-eight".