87819989197825 has 24 divisors (see below), whose sum is σ = 109400844069720. Its totient is φ = 69931194777600.

The previous prime is 87819989197813. The next prime is 87819989197859. The reversal of 87819989197825 is 52879198991878.

It is a happy number.

It is a Cunningham number, because it is equal to 9371232²+1.

It can be written as a sum of positive squares in 12 ways, for example, as 6885082115136 + 80934907082689 = 2623944^2 + 8996383^2 .

It is not a de Polignac number, because 87819989197825 - 2²³ = 87819980809217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 87819989197825.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3722941 + ... + 13765909.

It is an arithmetic number, because the mean of its divisors is an integer number (4558368502905).

Almost surely, 2^{87819989197825} is an apocalyptic number.

It is an amenable number.

87819989197825 is a deficient number, since it is larger than the sum of its proper divisors (21580854871895).

87819989197825 is a wasteful number, since it uses less digits than its factorization.

87819989197825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10044597 (or 10044592 counting only the distinct ones).

The product of its digits is 13168189440, while the sum is 91.

The spelling of 87819989197825 in words is "eighty-seven trillion, eight hundred nineteen billion, nine hundred eighty-nine million, one hundred ninety-seven thousand, eight hundred twenty-five".