8121872215 has 4 divisors (see below), whose sum is σ = 9746246664. Its totient is φ = 6497497768.

The previous prime is 8121872167. The next prime is 8121872233. The reversal of 8121872215 is 5122781218.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8121872215 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 812187217 + ... + 812187226.

It is an arithmetic number, because the mean of its divisors is an integer number (2436561666).

Almost surely, 2^8121872215 is an apocalyptic number.

8121872215 is a deficient number, since it is larger than the sum of its proper divisors (1624374449).

8121872215 is a wasteful number, since it uses less digits than its factorization.

8121872215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1624374448.

The product of its digits is 17920, while the sum is 37.

The square root of 8121872215 is about 90121.4303870062. The cubic root of 8121872215 is about 2010.1048776576.

The spelling of 8121872215 in words is "eight billion, one hundred twenty-one million, eight hundred seventy-two thousand, two hundred fifteen".