72138111 has 4 divisors (see below), whose sum is σ = 96184152. Its totient is φ = 48092072.

The previous prime is 72138107. The next prime is 72138113. The reversal of 72138111 is 11183127.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 72138111 - 2² = 72138107 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72138113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12023016 + ... + 12023021.

It is an arithmetic number, because the mean of its divisors is an integer number (24046038).

Almost surely, 2^72138111 is an apocalyptic number.

72138111 is a deficient number, since it is larger than the sum of its proper divisors (24046041).

72138111 is a wasteful number, since it uses less digits than its factorization.

72138111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24046040.

The product of its digits is 336, while the sum is 24.

The square root of 72138111 is about 8493.4157439749. The cubic root of 72138111 is about 416.2825969837.

The spelling of 72138111 in words is "seventy-two million, one hundred thirty-eight thousand, one hundred eleven".