28651280 has 60 divisors (see below), whose sum is σ = 77500620. Its totient is φ = 9821952.

The previous prime is 28651279. The next prime is 28651291. The reversal of 28651280 is 8215682.

It can be written as a sum of positive squares in 2 ways, for example, as 11478544 + 17172736 = 3388^2 + 4144^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 266 + ... + 7574.

It is an arithmetic number, because the mean of its divisors is an integer number (1291677).

Almost surely, 2^28651280 is an apocalyptic number.

28651280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28651280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38750310).

28651280 is an abundant number, since it is smaller than the sum of its proper divisors (48849340).

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

28651280 is a wasteful number, since it uses less digits than its factorization.

28651280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7336 (or 7323 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 28651280 is about 5352.6890438358. The cubic root of 28651280 is about 305.9952439206.

The spelling of 28651280 in words is "twenty-eight million, six hundred fifty-one thousand, two hundred eighty".