1391543 has 4 divisors (see below), whose sum is σ = 1394328. Its totient is φ = 1388760.

The previous prime is 1391521. The next prime is 1391549. The reversal of 1391543 is 3451931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3451931 = 7 ⋅493133.

It is a cyclic number.

It is not a de Polignac number, because 1391543 - 2⁶ = 1391479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1391549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 413 + ... + 1718.

It is an arithmetic number, because the mean of its divisors is an integer number (348582).

2^1391543 is an apocalyptic number.

1391543 is a deficient number, since it is larger than the sum of its proper divisors (2785).

1391543 is an equidigital number, since it uses as much as digits as its factorization.

1391543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2784.

The product of its digits is 1620, while the sum is 26.

The square root of 1391543 is about 1179.6368085135. The cubic root of 1391543 is about 111.6431831016.

The spelling of 1391543 in words is "one million, three hundred ninety-one thousand, five hundred forty-three".