1399789 has 2 divisors, whose sum is σ = 1399790. Its totient is φ = 1399788.

The previous prime is 1399777. The next prime is 1399793. The reversal of 1399789 is 9879931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1247689 + 152100 = 1117^2 + 390^2 .

It is a cyclic number.

It is not a de Polignac number, because 1399789 - 2¹³ = 1391597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1399709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 699894 + 699895.

It is an arithmetic number, because the mean of its divisors is an integer number (699895).

2^1399789 is an apocalyptic number.

It is an amenable number.

1399789 is a deficient number, since it is larger than the sum of its proper divisors (1).

1399789 is an equidigital number, since it uses as much as digits as its factorization.

1399789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 122472, while the sum is 46.

The square root of 1399789 is about 1183.1267894862. The cubic root of 1399789 is about 111.8632738456.

The spelling of 1399789 in words is "one million, three hundred ninety-nine thousand, seven hundred eighty-nine".