1387789 has 4 divisors (see below), whose sum is σ = 1494556. Its totient is φ = 1281024.

The previous prime is 1387783. The next prime is 1387801. The reversal of 1387789 is 9877831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9877831 = 43 ⋅229717.

It can be written as a sum of positive squares in 2 ways, for example, as 550564 + 837225 = 742^2 + 915^2 .

It is a cyclic number.

It is not a de Polignac number, because 1387789 - 2³ = 1387781 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 (1387781) 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, 53364 + ... + 53389.

It is an arithmetic number, because the mean of its divisors is an integer number (373639).

2^1387789 is an apocalyptic number.

It is an amenable number.

1387789 is a deficient number, since it is larger than the sum of its proper divisors (106767).

1387789 is a wasteful number, since it uses less digits than its factorization.

1387789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106766.

The product of its digits is 84672, while the sum is 43.

The square root of 1387789 is about 1178.0445662198. The cubic root of 1387789 is about 111.5426984945.

The spelling of 1387789 in words is "one million, three hundred eighty-seven thousand, seven hundred eighty-nine".