72157729 has 8 divisors (see below), whose sum is σ = 83393280. Its totient is φ = 61154016.

The previous prime is 72157721. The next prime is 72157747. The reversal of 72157729 is 92775127.

It is a happy number.

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

It is not a de Polignac number, because 72157729 - 2³ = 72157721 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72157691 and 72157700.

It is not an unprimeable number, because it can be changed into a prime (72157721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57289 + ... + 58534.

It is an arithmetic number, because the mean of its divisors is an integer number (10424160).

Almost surely, 2^72157729 is an apocalyptic number.

It is an amenable number.

72157729 is a deficient number, since it is larger than the sum of its proper divisors (11235551).

72157729 is a wasteful number, since it uses less digits than its factorization.

72157729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115919.

The product of its digits is 61740, while the sum is 40.

The square root of 72157729 is about 8494.5705600695. The cubic root of 72157729 is about 416.3203296592.

The spelling of 72157729 in words is "seventy-two million, one hundred fifty-seven thousand, seven hundred twenty-nine".