1381685 has 4 divisors (see below), whose sum is σ = 1658028. Its totient is φ = 1105344.

The previous prime is 1381649. The next prime is 1381693. The reversal of 1381685 is 5861831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5861831 = 71 ⋅82561.

It can be written as a sum of positive squares in 2 ways, for example, as 167281 + 1214404 = 409^2 + 1102^2 .

It is a cyclic number.

It is not a de Polignac number, because 1381685 - 2⁶ = 1381621 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138164 + ... + 138173.

It is an arithmetic number, because the mean of its divisors is an integer number (414507).

2^1381685 is an apocalyptic number.

It is an amenable number.

1381685 is a deficient number, since it is larger than the sum of its proper divisors (276343).

1381685 is an equidigital number, since it uses as much as digits as its factorization.

1381685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276342.

The product of its digits is 5760, while the sum is 32.

The square root of 1381685 is about 1175.4509772849. The cubic root of 1381685 is about 111.3789230464.

The spelling of 1381685 in words is "one million, three hundred eighty-one thousand, six hundred eighty-five".