1387993 has 4 divisors (see below), whose sum is σ = 1392768. Its totient is φ = 1383220.

The previous prime is 1387987. The next prime is 1388003. The reversal of 1387993 is 3997831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3997831 = 337 ⋅11863.

It is a cyclic number.

It is not a de Polignac number, because 1387993 - 2⁵ = 1387961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1387913) 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, 1921 + ... + 2542.

It is an arithmetic number, because the mean of its divisors is an integer number (348192).

2^1387993 is an apocalyptic number.

It is an amenable number.

1387993 is a deficient number, since it is larger than the sum of its proper divisors (4775).

1387993 is an equidigital number, since it uses as much as digits as its factorization.

1387993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4774.

The product of its digits is 40824, while the sum is 40.

The square root of 1387993 is about 1178.1311471988. The cubic root of 1387993 is about 111.5481636854.

The spelling of 1387993 in words is "one million, three hundred eighty-seven thousand, nine hundred ninety-three".