28611280 has 40 divisors (see below), whose sum is σ = 67198824. Its totient is φ = 11328000.

The previous prime is 28611263. The next prime is 28611299. The reversal of 28611280 is 8211682.

It can be written as a sum of positive squares in 4 ways, for example, as 8433216 + 20178064 = 2904^2 + 4492^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 6310 + ... + 9850.

Almost surely, 2^28611280 is an apocalyptic number.

28611280 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 28611280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33599412).

28611280 is an abundant number, since it is smaller than the sum of its proper divisors (38587544).

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

28611280 is a wasteful number, since it uses less digits than its factorization.

28611280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3655 (or 3649 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 28611280 is about 5348.9512990866. The cubic root of 28611280 is about 305.8527777995.

The spelling of 28611280 in words is "twenty-eight million, six hundred eleven thousand, two hundred eighty".