729870857 has 2 divisors, whose sum is σ = 729870858. Its totient is φ = 729870856.

The previous prime is 729870839. The next prime is 729870859. The reversal of 729870857 is 758078927.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 612018121 + 117852736 = 24739^2 + 10856^2 .

It is a cyclic number.

It is not a de Polignac number, because 729870857 - 2¹⁸ = 729608713 is a prime.

It is a super-2 number, since 2×729870857² = 1065422935795828898, which contains 22 as substring.

Together with 729870859, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 729870799 and 729870808.

It is not a weakly prime, because it can be changed into another prime (729870859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364935428 + 364935429.

It is an arithmetic number, because the mean of its divisors is an integer number (364935429).

Almost surely, 2^729870857 is an apocalyptic number.

It is an amenable number.

729870857 is a deficient number, since it is larger than the sum of its proper divisors (1).

729870857 is an equidigital number, since it uses as much as digits as its factorization.

729870857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1975680, while the sum is 53.

The square root of 729870857 is about 27016.1221680685. The cubic root of 729870857 is about 900.3582347561.

The spelling of 729870857 in words is "seven hundred twenty-nine million, eight hundred seventy thousand, eight hundred fifty-seven".