157717729 has 6 divisors (see below), whose sum is σ = 170783286. Its totient is φ = 145585440.

The previous prime is 157717723. The next prime is 157717751. The reversal of 157717729 is 927717751.

It can be written as a sum of positive squares in 3 ways, for example, as 14077504 + 143640225 = 3752^2 + 11985^2 .

It is not a de Polignac number, because 157717729 - 2⁵ = 157717697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (157717723) 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 5 ways as a sum of consecutive naturals, for example, 466452 + ... + 466789.

It is an arithmetic number, because the mean of its divisors is an integer number (28463881).

Almost surely, 2^157717729 is an apocalyptic number.

It is an amenable number.

157717729 is a deficient number, since it is larger than the sum of its proper divisors (13065557).

157717729 is an equidigital number, since it uses as much as digits as its factorization.

157717729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933267 (or 933254 counting only the distinct ones).

The product of its digits is 216090, while the sum is 46.

The square root of 157717729 is about 12558.5719331459. The cubic root of 157717729 is about 540.2898866485.

It can be divided in two parts, 1577 and 17729, that added together give a triangular number (19306 = T₁₉₆).

The spelling of 157717729 in words is "one hundred fifty-seven million, seven hundred seventeen thousand, seven hundred twenty-nine".