8101721191 has 4 divisors (see below), whose sum is σ = 8101926352. Its totient is φ = 8101516032.

The previous prime is 8101721183. The next prime is 8101721197. The reversal of 8101721191 is 1911271018.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1911271018 = 2 ⋅955635509.

It is a cyclic number.

It is not a de Polignac number, because 8101721191 - 2³ = 8101721183 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 (8101721197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22515 + ... + 129268.

It is an arithmetic number, because the mean of its divisors is an integer number (2025481588).

Almost surely, 2^8101721191 is an apocalyptic number.

8101721191 is a deficient number, since it is larger than the sum of its proper divisors (205161).

8101721191 is a wasteful number, since it uses less digits than its factorization.

8101721191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205160.

The product of its (nonzero) digits is 1008, while the sum is 31.

The square root of 8101721191 is about 90009.5616643032. The cubic root of 8101721191 is about 2008.4410897978.

The spelling of 8101721191 in words is "eight billion, one hundred one million, seven hundred twenty-one thousand, one hundred ninety-one".