28720305716 has 24 divisors (see below), whose sum is σ = 53605499976. Its totient is φ = 13416780800.

The previous prime is 28720305709. The next prime is 28720305721. The reversal of 28720305716 is 61750302782.

It can be written as a sum of positive squares in 4 ways, for example, as 17704963600 + 11015342116 = 133060^2 + 104954^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1532135 + ... + 1550766.

It is an arithmetic number, because the mean of its divisors is an integer number (2233562499).

Almost surely, 2^28720305716 is an apocalyptic number.

It is an amenable number.

28720305716 is a deficient number, since it is larger than the sum of its proper divisors (24885194260).

28720305716 is a wasteful number, since it uses less digits than its factorization.

28720305716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3083059 (or 3083057 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 41.

The spelling of 28720305716 in words is "twenty-eight billion, seven hundred twenty million, three hundred five thousand, seven hundred sixteen".