8121931972 has 48 divisors (see below), whose sum is σ = 17798796288. Its totient is φ = 3150421920.

The previous prime is 8121931967. The next prime is 8121931991. The reversal of 8121931972 is 2791391218.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11833 + ... + 127999.

It is an arithmetic number, because the mean of its divisors is an integer number (370808256).

Almost surely, 2^8121931972 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8121931972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8899398144).

8121931972 is an abundant number, since it is smaller than the sum of its proper divisors (9676864316).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8121931972 is a wasteful number, since it uses less digits than its factorization.

8121931972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116416 (or 116414 counting only the distinct ones).

The product of its digits is 54432, while the sum is 43.

The square root of 8121931972 is about 90121.7619224125. The cubic root of 8121931972 is about 2010.1098074545.

The spelling of 8121931972 in words is "eight billion, one hundred twenty-one million, nine hundred thirty-one thousand, nine hundred seventy-two".