87513833581 has 4 divisors (see below), whose sum is σ = 87608036700. Its totient is φ = 87419630464.

The previous prime is 87513833569. The next prime is 87513833609. The reversal of 87513833581 is 18533831578.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18533831578 = 2 ⋅9266915789.

It can be written as a sum of positive squares in 2 ways, for example, as 10544209225 + 76969624356 = 102685^2 + 277434^2 .

It is a cyclic number.

It is not a de Polignac number, because 87513833581 - 2²⁵ = 87480279149 is a prime.

It is a super-2 number, since 2×87513833581² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87513837581) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47100166 + ... + 47102023.

It is an arithmetic number, because the mean of its divisors is an integer number (21902009175).

Almost surely, 2^87513833581 is an apocalyptic number.

It is an amenable number.

87513833581 is a deficient number, since it is larger than the sum of its proper divisors (94203119).

87513833581 is an equidigital number, since it uses as much as digits as its factorization.

87513833581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94203118.

The product of its digits is 2419200, while the sum is 52.

The spelling of 87513833581 in words is "eighty-seven billion, five hundred thirteen million, eight hundred thirty-three thousand, five hundred eighty-one".