28778634 has 12 divisors (see below), whose sum is σ = 62353746. Its totient is φ = 9592872.

The previous prime is 28778627. The next prime is 28778647. The reversal of 28778634 is 43687782.

It is a happy number.

28778634 is a `hidden beast` number, since 2 + 8 + 7 + 7 + 8 + 634 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20223009 + 8555625 = 4497^2 + 2925^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28778634.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 799389 + ... + 799424.

Almost surely, 2^28778634 is an apocalyptic number.

28778634 is an abundant number, since it is smaller than the sum of its proper divisors (33575112).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28778634 is a wasteful number, since it uses less digits than its factorization.

28778634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1598821 (or 1598818 counting only the distinct ones).

The product of its digits is 451584, while the sum is 45.

The square root of 28778634 is about 5364.5721171404. The cubic root of 28778634 is about 306.4479534301.

It can be divided in two parts, 2877 and 8634, that added together give a palindrome (11511).

The spelling of 28778634 in words is "twenty-eight million, seven hundred seventy-eight thousand, six hundred thirty-four".