1385729 has 4 divisors (see below), whose sum is σ = 1388100. Its totient is φ = 1383360.

The previous prime is 1385693. The next prime is 1385743. The reversal of 1385729 is 9275831.

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.

It can be written as a sum of positive squares in 2 ways, for example, as 1270129 + 115600 = 1127^2 + 340^2 .

It is a cyclic number.

It is not a de Polignac number, because 1385729 - 2²⁰ = 337153 is a prime.

It is a super-2 number, since 2×1385729² = 3840489722882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1385749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 389 + ... + 1709.

It is an arithmetic number, because the mean of its divisors is an integer number (347025).

2^1385729 is an apocalyptic number.

It is an amenable number.

1385729 is a deficient number, since it is larger than the sum of its proper divisors (2371).

1385729 is a wasteful number, since it uses less digits than its factorization.

1385729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2370.

The product of its digits is 15120, while the sum is 35.

The square root of 1385729 is about 1177.1699112702. The cubic root of 1385729 is about 111.4874807477.

The spelling of 1385729 in words is "one million, three hundred eighty-five thousand, seven hundred twenty-nine".