72111423121 has 4 divisors (see below), whose sum is σ = 75906761200. Its totient is φ = 68316085044.

The previous prime is 72111423119. The next prime is 72111423151. The reversal of 72111423121 is 12132411127.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72111423121 - 2¹ = 72111423119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72111423151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1897669011 + ... + 1897669048.

It is an arithmetic number, because the mean of its divisors is an integer number (18976690300).

Almost surely, 2^72111423121 is an apocalyptic number.

It is an amenable number.

72111423121 is a deficient number, since it is larger than the sum of its proper divisors (3795338079).

72111423121 is a wasteful number, since it uses less digits than its factorization.

72111423121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3795338078.

The product of its digits is 672, while the sum is 25.

Adding to 72111423121 its reverse (12132411127), we get a palindrome (84243834248).

The spelling of 72111423121 in words is "seventy-two billion, one hundred eleven million, four hundred twenty-three thousand, one hundred twenty-one".