72145123 has 4 divisors (see below), whose sum is σ = 72301408. Its totient is φ = 71988840.

The previous prime is 72145121. The next prime is 72145163. The reversal of 72145123 is 32154127.

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 72145123 - 2¹ = 72145121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72145121) 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 3 ways as a sum of consecutive naturals, for example, 77448 + ... + 78373.

It is an arithmetic number, because the mean of its divisors is an integer number (18075352).

Almost surely, 2^72145123 is an apocalyptic number.

72145123 is a deficient number, since it is larger than the sum of its proper divisors (156285).

72145123 is a wasteful number, since it uses less digits than its factorization.

72145123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156284.

The product of its digits is 1680, while the sum is 25.

The square root of 72145123 is about 8493.8285242875. The cubic root of 72145123 is about 416.2960844406.

The spelling of 72145123 in words is "seventy-two million, one hundred forty-five thousand, one hundred twenty-three".