1385721 has 16 divisors (see below), whose sum is σ = 2174400. Its totient is φ = 869184.

The previous prime is 1385693. The next prime is 1385743. The reversal of 1385721 is 1275831.

It is not a de Polignac number, because 1385721 - 2¹⁰ = 1384697 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1385521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1051 + ... + 1968.

It is an arithmetic number, because the mean of its divisors is an integer number (135900).

2^1385721 is an apocalyptic number.

It is an amenable number.

1385721 is a deficient number, since it is larger than the sum of its proper divisors (788679).

1385721 is a wasteful number, since it uses less digits than its factorization.

1385721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3045 (or 3039 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 1385721 is about 1177.1665132852. The cubic root of 1385721 is about 111.4872662032.

The spelling of 1385721 in words is "one million, three hundred eighty-five thousand, seven hundred twenty-one".