75721503506505 has 16 divisors (see below), whose sum is σ = 121688125464384. Its totient is φ = 40206895252160.

The previous prime is 75721503506491. The next prime is 75721503506507. The reversal of 75721503506505 is 50560530512757.

It is not a de Polignac number, because 75721503506505 - 2¹³ = 75721503498313 is a prime.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (75721503506507) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11119160106 + ... + 11119166915.

It is an arithmetic number, because the mean of its divisors is an integer number (7605507841524).

Almost surely, 2^{75721503506505} is an apocalyptic number.

It is an amenable number.

75721503506505 is a deficient number, since it is larger than the sum of its proper divisors (45966621957879).

75721503506505 is a wasteful number, since it uses less digits than its factorization.

75721503506505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22238327256.

The product of its (nonzero) digits is 5512500, while the sum is 51.

The spelling of 75721503506505 in words is "seventy-five trillion, seven hundred twenty-one billion, five hundred three million, five hundred six thousand, five hundred five".