8018705821 has 4 divisors (see below), whose sum is σ = 9164235232. Its totient is φ = 6873176412.

The previous prime is 8018705803. The next prime is 8018705857. The reversal of 8018705821 is 1285078108.

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 not a de Polignac number, because 8018705821 - 2⁵ = 8018705789 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 (8018705021) 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, 572764695 + ... + 572764708.

It is an arithmetic number, because the mean of its divisors is an integer number (2291058808).

Almost surely, 2^8018705821 is an apocalyptic number.

It is an amenable number.

8018705821 is a deficient number, since it is larger than the sum of its proper divisors (1145529411).

8018705821 is a wasteful number, since it uses less digits than its factorization.

8018705821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1145529410.

The product of its (nonzero) digits is 35840, while the sum is 40.

The square root of 8018705821 is about 89547.2267633119. The cubic root of 8018705821 is about 2001.5576050350.

The spelling of 8018705821 in words is "eight billion, eighteen million, seven hundred five thousand, eight hundred twenty-one".