8721121287 has 4 divisors (see below), whose sum is σ = 11628161720. Its totient is φ = 5814080856.

The previous prime is 8721121273. The next prime is 8721121319. The reversal of 8721121287 is 7821211278.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 8721121287 - 2¹⁰ = 8721120263 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 (8721123287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1453520212 + ... + 1453520217.

It is an arithmetic number, because the mean of its divisors is an integer number (2907040430).

Almost surely, 2^8721121287 is an apocalyptic number.

8721121287 is a deficient number, since it is larger than the sum of its proper divisors (2907040433).

8721121287 is a wasteful number, since it uses less digits than its factorization.

8721121287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2907040432.

The product of its digits is 25088, while the sum is 39.

The square root of 8721121287 is about 93386.9438786815. The cubic root of 8721121287 is about 2058.3731529145.

The spelling of 8721121287 in words is "eight billion, seven hundred twenty-one million, one hundred twenty-one thousand, two hundred eighty-seven".