28138648 has 16 divisors (see below), whose sum is σ = 54186480. Its totient is φ = 13688928.

The previous prime is 28138631. The next prime is 28138651. The reversal of 28138648 is 84683182.

It is a super-2 number, since 2×28138648² = 1583567022535808, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28138648.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47236 + ... + 47827.

It is an arithmetic number, because the mean of its divisors is an integer number (3386655).

Almost surely, 2^28138648 is an apocalyptic number.

It is an amenable number.

28138648 is a deficient number, since it is larger than the sum of its proper divisors (26047832).

28138648 is a wasteful number, since it uses less digits than its factorization.

28138648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95106 (or 95102 counting only the distinct ones).

The product of its digits is 73728, while the sum is 40.

The square root of 28138648 is about 5304.5874486146. The cubic root of 28138648 is about 304.1592828716.

The spelling of 28138648 in words is "twenty-eight million, one hundred thirty-eight thousand, six hundred forty-eight".