42775528721 has 4 divisors (see below), whose sum is σ = 42827128500. Its totient is φ = 42723928944.

The previous prime is 42775528717. The next prime is 42775528753. The reversal of 42775528721 is 12782557724.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21427104400 + 21348424321 = 146380^2 + 146111^2 .

It is a cyclic number.

It is not a de Polignac number, because 42775528721 - 2² = 42775528717 is a prime.

It is a super-2 number, since 2×42775528721² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42775528721.

It is not an unprimeable number, because it can be changed into a prime (42775528711) 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 3 ways as a sum of consecutive naturals, for example, 25798646 + ... + 25800303.

It is an arithmetic number, because the mean of its divisors is an integer number (10706782125).

Almost surely, 2^42775528721 is an apocalyptic number.

It is an amenable number.

42775528721 is a deficient number, since it is larger than the sum of its proper divisors (51599779).

42775528721 is an equidigital number, since it uses as much as digits as its factorization.

42775528721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51599778.

The product of its digits is 2195200, while the sum is 50.

The spelling of 42775528721 in words is "forty-two billion, seven hundred seventy-five million, five hundred twenty-eight thousand, seven hundred twenty-one".