800042087521 has 4 divisors (see below), whose sum is σ = 801016561044. Its totient is φ = 799067614000.

The previous prime is 800042087503. The next prime is 800042087557. The reversal of 800042087521 is 125780240008.

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 172245750625 + 627796336896 = 415025^2 + 792336^2 .

It is a cyclic number.

It is not a de Polignac number, because 800042087521 - 2¹³ = 800042079329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (800042087821) 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, 487235530 + ... + 487237171.

It is an arithmetic number, because the mean of its divisors is an integer number (200254140261).

Almost surely, 2^800042087521 is an apocalyptic number.

It is an amenable number.

800042087521 is a deficient number, since it is larger than the sum of its proper divisors (974473523).

800042087521 is an equidigital number, since it uses as much as digits as its factorization.

800042087521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 974473522.

The product of its (nonzero) digits is 35840, while the sum is 37.

The spelling of 800042087521 in words is "eight hundred billion, forty-two million, eighty-seven thousand, five hundred twenty-one".