28661760 has 144 divisors (see below), whose sum is σ = 99655920. Its totient is φ = 7618560.

The previous prime is 28661713. The next prime is 28661783. The reversal of 28661760 is 6716682.

28661760 = 135² + 136² + ... + 445².

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 92005 + ... + 92315.

It is an arithmetic number, because the mean of its divisors is an integer number (692055).

Almost surely, 2^28661760 is an apocalyptic number.

28661760 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 28661760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49827960).

28661760 is an abundant number, since it is smaller than the sum of its proper divisors (70994160).

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

28661760 is a wasteful number, since it uses less digits than its factorization.

28661760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344 (or 321 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 28661760 is about 5353.6679015419. The cubic root of 28661760 is about 306.0325481206.

The spelling of 28661760 in words is "twenty-eight million, six hundred sixty-one thousand, seven hundred sixty".