28882640 has 20 divisors (see below), whose sum is σ = 67152324. Its totient is φ = 11553024.

The previous prime is 28882621. The next prime is 28882657. The reversal of 28882640 is 4628882.

It can be written as a sum of positive squares in 2 ways, for example, as 20286016 + 8596624 = 4504^2 + 2932^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 28882594 and 28882603.

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, 180437 + ... + 180596.

Almost surely, 2^28882640 is an apocalyptic number.

28882640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28882640 is an abundant number, since it is smaller than the sum of its proper divisors (38269684).

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

28882640 is a wasteful number, since it uses less digits than its factorization.

28882640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361046 (or 361040 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 38.

The square root of 28882640 is about 5374.2571579708. The cubic root of 28882640 is about 306.8166772907.

It can be divided in two parts, 288 and 82640, that added together give a palindrome (82928).

The spelling of 28882640 in words is "twenty-eight million, eight hundred eighty-two thousand, six hundred forty".