72170717 has 4 divisors (see below), whose sum is σ = 72187836. Its totient is φ = 72153600.

The previous prime is 72170699. The next prime is 72170731. The reversal of 72170717 is 71707127.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 71707127 = 1579 ⋅45413.

It can be written as a sum of positive squares in 2 ways, for example, as 62504836 + 9665881 = 7906^2 + 3109^2 .

It is a cyclic number.

It is not a de Polignac number, because 72170717 - 2²² = 67976413 is a prime.

It is a super-2 number, since 2×72170717² = 10417224784588178, 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 (72170737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2717 + ... + 12317.

It is an arithmetic number, because the mean of its divisors is an integer number (18046959).

Almost surely, 2^72170717 is an apocalyptic number.

It is an amenable number.

72170717 is a deficient number, since it is larger than the sum of its proper divisors (17119).

72170717 is an equidigital number, since it uses as much as digits as its factorization.

72170717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17118.

The product of its (nonzero) digits is 4802, while the sum is 32.

The square root of 72170717 is about 8495.3350139944. The cubic root of 72170717 is about 416.3453066280.

The spelling of 72170717 in words is "seventy-two million, one hundred seventy thousand, seven hundred seventeen".