72161717 has 4 divisors (see below), whose sum is σ = 72185196. Its totient is φ = 72138240.

The previous prime is 72161701. The next prime is 72161723. The reversal of 72161717 is 71716127.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1164241 + 70997476 = 1079^2 + 8426^2 .

It is a cyclic number.

It is not a de Polignac number, because 72161717 - 2⁴ = 72161701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72161737) 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, 6284 + ... + 13557.

It is an arithmetic number, because the mean of its divisors is an integer number (18046299).

Almost surely, 2^72161717 is an apocalyptic number.

It is an amenable number.

72161717 is a deficient number, since it is larger than the sum of its proper divisors (23479).

72161717 is a wasteful number, since it uses less digits than its factorization.

72161717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23478.

The product of its digits is 4116, while the sum is 32.

The square root of 72161717 is about 8494.8052950024. The cubic root of 72161717 is about 416.3279992228.

The spelling of 72161717 in words is "seventy-two million, one hundred sixty-one thousand, seven hundred seventeen".