28709532280 has 128 divisors (see below), whose sum is σ = 76031524800. Its totient is φ = 9618739200.

The previous prime is 28709532251. The next prime is 28709532283. The reversal of 28709532280 is 8223590782.

It is a self number, because there is not a number n which added to its sum of digits gives 28709532280.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28709532283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3250270 + ... + 3259090.

Almost surely, 2^28709532280 is an apocalyptic number.

28709532280 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 28709532280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38015762400).

28709532280 is an abundant number, since it is smaller than the sum of its proper divisors (47321992520).

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

28709532280 is a wasteful number, since it uses less digits than its factorization.

28709532280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9425 (or 9421 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 46.

The spelling of 28709532280 in words is "twenty-eight billion, seven hundred nine million, five hundred thirty-two thousand, two hundred eighty".