28099505780 has 18 divisors (see below), whose sum is σ = 59010536466. Its totient is φ = 11239502448.

The previous prime is 28099505729. The next prime is 28099505807. The reversal of 28099505780 is 8750599082.

It can be written as a sum of positive squares in only one way, i.e., 22479604624 + 5619901156 = 149932^2 + 74966^2 .

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 730919 + ... + 768401.

It is an arithmetic number, because the mean of its divisors is an integer number (3278363137).

Almost surely, 2^28099505780 is an apocalyptic number.

28099505780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28099505780 is an abundant number, since it is smaller than the sum of its proper divisors (30911030686).

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

28099505780 is an frugal number, since it uses more digits than its factorization.

28099505780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74975 (or 37490 counting only the distinct ones).

The product of its (nonzero) digits is 1814400, while the sum is 53.

The spelling of 28099505780 in words is "twenty-eight billion, ninety-nine million, five hundred five thousand, seven hundred eighty".