1387391 has 4 divisors (see below), whose sum is σ = 1401792. Its totient is φ = 1372992.

The previous prime is 1387367. The next prime is 1387403. The reversal of 1387391 is 1937831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1937831 = 7 ⋅276833.

It is a cyclic number.

It is not a de Polignac number, because 1387391 - 2⁶ = 1387327 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 (1387691) 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, 7055 + ... + 7248.

It is an arithmetic number, because the mean of its divisors is an integer number (350448).

2^1387391 is an apocalyptic number.

1387391 is a deficient number, since it is larger than the sum of its proper divisors (14401).

1387391 is an equidigital number, since it uses as much as digits as its factorization.

1387391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14400.

The product of its digits is 4536, while the sum is 32.

The square root of 1387391 is about 1177.8756301070. The cubic root of 1387391 is about 111.5320344722.

The spelling of 1387391 in words is "one million, three hundred eighty-seven thousand, three hundred ninety-one".