72745181 has 4 divisors (see below), whose sum is σ = 72951612. Its totient is φ = 72538752.

The previous prime is 72745177. The next prime is 72745199. The reversal of 72745181 is 18154727.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18154727 = 1997 ⋅9091.

It can be written as a sum of positive squares in 2 ways, for example, as 22477081 + 50268100 = 4741^2 + 7090^2 .

It is a cyclic number.

It is not a de Polignac number, because 72745181 - 2² = 72745177 is a prime.

It is a super-2 number, since 2×72745181² = 10583722717445522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72745381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102686 + ... + 103391.

It is an arithmetic number, because the mean of its divisors is an integer number (18237903).

Almost surely, 2^72745181 is an apocalyptic number.

It is an amenable number.

72745181 is a deficient number, since it is larger than the sum of its proper divisors (206431).

72745181 is a wasteful number, since it uses less digits than its factorization.

72745181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206430.

The product of its digits is 15680, while the sum is 35.

The square root of 72745181 is about 8529.0785551547. The cubic root of 72745181 is about 417.4470627420.

The spelling of 72745181 in words is "seventy-two million, seven hundred forty-five thousand, one hundred eighty-one".