1389987 has 8 divisors (see below), whose sum is σ = 2059280. Its totient is φ = 926640.

The previous prime is 1389961. The next prime is 1389989. The reversal of 1389987 is 7899831.

It is not a de Polignac number, because 1389987 - 2¹⁰ = 1388963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1389989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25714 + ... + 25767.

It is an arithmetic number, because the mean of its divisors is an integer number (257410).

2^1389987 is an apocalyptic number.

1389987 is a deficient number, since it is larger than the sum of its proper divisors (669293).

1389987 is an equidigital number, since it uses as much as digits as its factorization.

1389987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51490 (or 51484 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 1389987 is about 1178.9770990142. The cubic root of 1389987 is about 111.6015550714.

It can be divided in two parts, 13 and 89987, that added together give a square (90000 = 300²).

The spelling of 1389987 in words is "one million, three hundred eighty-nine thousand, nine hundred eighty-seven".