87684164821 has 4 divisors (see below), whose sum is σ = 95655452544. Its totient is φ = 79712877100.

The previous prime is 87684164809. The next prime is 87684164831. The reversal of 87684164821 is 12846148678.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87684164821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87684164801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3985643845 + ... + 3985643866.

It is an arithmetic number, because the mean of its divisors is an integer number (23913863136).

Almost surely, 2^87684164821 is an apocalyptic number.

It is an amenable number.

87684164821 is a deficient number, since it is larger than the sum of its proper divisors (7971287723).

87684164821 is a wasteful number, since it uses less digits than its factorization.

87684164821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7971287722.

The product of its digits is 4128768, while the sum is 55.

The spelling of 87684164821 in words is "eighty-seven billion, six hundred eighty-four million, one hundred sixty-four thousand, eight hundred twenty-one".