72151221121 has 16 divisors (see below), whose sum is σ = 84511244160. Its totient is φ = 60305857920.

The previous prime is 72151221071. The next prime is 72151221137. The reversal of 72151221121 is 12112215127.

It is not a de Polignac number, because 72151221121 - 2¹¹ = 72151219073 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72151221521) 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 15 ways as a sum of consecutive naturals, for example, 533050 + ... + 654556.

It is an arithmetic number, because the mean of its divisors is an integer number (5281952760).

Almost surely, 2^72151221121 is an apocalyptic number.

It is an amenable number.

72151221121 is a deficient number, since it is larger than the sum of its proper divisors (12360023039).

72151221121 is a wasteful number, since it uses less digits than its factorization.

72151221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123624.

The product of its digits is 560, while the sum is 25.

Adding to 72151221121 its reverse (12112215127), we get a palindrome (84263436248).

The spelling of 72151221121 in words is "seventy-two billion, one hundred fifty-one million, two hundred twenty-one thousand, one hundred twenty-one".