72017257 has 8 divisors (see below), whose sum is σ = 77651784. Its totient is φ = 66396288.

The previous prime is 72017251. The next prime is 72017293. The reversal of 72017257 is 75271027.

It can be written as a sum of positive squares in 4 ways, for example, as 4596736 + 67420521 = 2144^2 + 8211^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72017257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72017251) 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 7 ways as a sum of consecutive naturals, for example, 9483 + ... + 15295.

It is an arithmetic number, because the mean of its divisors is an integer number (9706473).

Almost surely, 2^72017257 is an apocalyptic number.

It is an amenable number.

72017257 is a deficient number, since it is larger than the sum of its proper divisors (5634527).

72017257 is a wasteful number, since it uses less digits than its factorization.

72017257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6779.

The product of its (nonzero) digits is 6860, while the sum is 31.

The square root of 72017257 is about 8486.2981917913. The cubic root of 72017257 is about 416.0499989984.

The spelling of 72017257 in words is "seventy-two million, seventeen thousand, two hundred fifty-seven".