72175181 has 4 divisors (see below), whose sum is σ = 77727132. Its totient is φ = 66623232.

The previous prime is 72175177. The next prime is 72175189. The reversal of 72175181 is 18157127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18157127 = 619 ⋅29333.

It can be written as a sum of positive squares in 2 ways, for example, as 14945956 + 57229225 = 3866^2 + 7565^2 .

It is not a de Polignac number, because 72175181 - 2² = 72175177 is a prime.

It is a super-2 number, since 2×72175181² = 10418513504765522, 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 (72175189) 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, 2775956 + ... + 2775981.

It is an arithmetic number, because the mean of its divisors is an integer number (19431783).

Almost surely, 2^72175181 is an apocalyptic number.

It is an amenable number.

72175181 is a deficient number, since it is larger than the sum of its proper divisors (5551951).

72175181 is a wasteful number, since it uses less digits than its factorization.

72175181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5551950.

The product of its digits is 3920, while the sum is 32.

The square root of 72175181 is about 8495.5977423605. The cubic root of 72175181 is about 416.3538905672.

The spelling of 72175181 in words is "seventy-two million, one hundred seventy-five thousand, one hundred eighty-one".