87373821821 has 24 divisors (see below), whose sum is σ = 103522433280. Its totient is φ = 73252761120.

The previous prime is 87373821779. The next prime is 87373821827. The reversal of 87373821821 is 12812837378.

It is not a de Polignac number, because 87373821821 - 2³⁰ = 86300079997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 87373821821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87373821827) by changing a digit.

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, 1709840 + ... + 1760198.

It is an arithmetic number, because the mean of its divisors is an integer number (4313434720).

Almost surely, 2^87373821821 is an apocalyptic number.

It is an amenable number.

87373821821 is a deficient number, since it is larger than the sum of its proper divisors (16148611459).

87373821821 is a wasteful number, since it uses less digits than its factorization.

87373821821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51497 (or 51486 counting only the distinct ones).

The product of its digits is 903168, while the sum is 50.

The spelling of 87373821821 in words is "eighty-seven billion, three hundred seventy-three million, eight hundred twenty-one thousand, eight hundred twenty-one".