28690438 has 16 divisors (see below), whose sum is σ = 50770944. Its totient is φ = 11899080.

The previous prime is 28690423. The next prime is 28690439. The reversal of 28690438 is 83409682.

It is a self number, because there is not a number n which added to its sum of digits gives 28690438.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28690439) 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 7 ways as a sum of consecutive naturals, for example, 32620 + ... + 33487.

It is an arithmetic number, because the mean of its divisors is an integer number (3173184).

Almost surely, 2^28690438 is an apocalyptic number.

28690438 is a deficient number, since it is larger than the sum of its proper divisors (22080506).

28690438 is a wasteful number, since it uses less digits than its factorization.

28690438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66147.

The product of its (nonzero) digits is 82944, while the sum is 40.

The square root of 28690438 is about 5356.3455825777. The cubic root of 28690438 is about 306.1345827469.

The spelling of 28690438 in words is "twenty-eight million, six hundred ninety thousand, four hundred thirty-eight".