1290389 has 4 divisors (see below), whose sum is σ = 1312320. Its totient is φ = 1268460.

The previous prime is 1290379. The next prime is 1290427. The reversal of 1290389 is 9830921.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1290389 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1290319) 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, 10877 + ... + 10994.

It is an arithmetic number, because the mean of its divisors is an integer number (328080).

2^1290389 is an apocalyptic number.

It is an amenable number.

1290389 is a deficient number, since it is larger than the sum of its proper divisors (21931).

1290389 is an equidigital number, since it uses as much as digits as its factorization.

1290389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21930.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 1290389 is about 1135.9529039533. The cubic root of 1290389 is about 108.8696643757.

Adding to 1290389 its sum of digits (32), we get a triangular number (1290421 = T₁₆₀₆).

The spelling of 1290389 in words is "one million, two hundred ninety thousand, three hundred eighty-nine".