28720660055545 has 8 divisors (see below), whose sum is σ = 34582419345096. Its totient is φ = 22898109858816.

The previous prime is 28720660055491. The next prime is 28720660055569. The reversal of 28720660055545 is 54555006602782.

It can be written as a sum of positive squares in 4 ways, for example, as 14903143690681 + 13817516364864 = 3860459^2 + 3717192^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28720660055545 - 2³³ = 28712070120953 is a prime.

It is a Duffinian 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, 9802271592 + ... + 9802274521.

It is an arithmetic number, because the mean of its divisors is an integer number (4322802418137).

Almost surely, 2^{28720660055545} is an apocalyptic number.

It is an amenable number.

28720660055545 is a deficient number, since it is larger than the sum of its proper divisors (5861759289551).

28720660055545 is a wasteful number, since it uses less digits than its factorization.

28720660055545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19604546411.

The product of its (nonzero) digits is 20160000, while the sum is 55.

The spelling of 28720660055545 in words is "twenty-eight trillion, seven hundred twenty billion, six hundred sixty million, fifty-five thousand, five hundred forty-five".