8751660199021 has 4 divisors (see below), whose sum is σ = 8751669299100. Its totient is φ = 8751651098944.

The previous prime is 8751660199019. The next prime is 8751660199043. The reversal of 8751660199021 is 1209910661578.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 5859667455625 + 2891992743396 = 2420675^2 + 1700586^2 .

It is a cyclic number.

It is not a de Polignac number, because 8751660199021 - 2¹ = 8751660199019 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 (8751660199621) 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, 2910556 + ... + 5096533.

It is an arithmetic number, because the mean of its divisors is an integer number (2187917324775).

Almost surely, 2^{8751660199021} is an apocalyptic number.

It is an amenable number.

8751660199021 is a deficient number, since it is larger than the sum of its proper divisors (9100079).

8751660199021 is a wasteful number, since it uses less digits than its factorization.

8751660199021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9100078.

The product of its (nonzero) digits is 1632960, while the sum is 55.

The spelling of 8751660199021 in words is "eight trillion, seven hundred fifty-one billion, six hundred sixty million, one hundred ninety-nine thousand, twenty-one".