1391399 has 4 divisors (see below), whose sum is σ = 1473264. Its totient is φ = 1309536.

The previous prime is 1391393. The next prime is 1391407. The reversal of 1391399 is 9931931.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9931931 = 227 ⋅43753.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1391399 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 (1391393) 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, 40907 + ... + 40940.

It is an arithmetic number, because the mean of its divisors is an integer number (368316).

2^1391399 is an apocalyptic number.

1391399 is a deficient number, since it is larger than the sum of its proper divisors (81865).

1391399 is an equidigital number, since it uses as much as digits as its factorization.

1391399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81864.

The product of its digits is 6561, while the sum is 35.

The square root of 1391399 is about 1179.5757711991. The cubic root of 1391399 is about 111.6393319395.

The spelling of 1391399 in words is "one million, three hundred ninety-one thousand, three hundred ninety-nine".