1289285 has 4 divisors (see below), whose sum is σ = 1547148. Its totient is φ = 1031424.

The previous prime is 1289273. The next prime is 1289287. The reversal of 1289285 is 5829821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 209764 + 1079521 = 458^2 + 1039^2 .

It is a cyclic number.

It is not a de Polignac number, because 1289285 - 2¹⁶ = 1223749 is a prime.

It is a super-2 number, since 2×1289285² = 3324511622450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1289287) 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, 128924 + ... + 128933.

It is an arithmetic number, because the mean of its divisors is an integer number (386787).

2^1289285 is an apocalyptic number.

It is an amenable number.

1289285 is a deficient number, since it is larger than the sum of its proper divisors (257863).

1289285 is an equidigital number, since it uses as much as digits as its factorization.

1289285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257862.

The product of its digits is 11520, while the sum is 35.

The square root of 1289285 is about 1135.4668643338. The cubic root of 1289285 is about 108.8386074869.

The spelling of 1289285 in words is "one million, two hundred eighty-nine thousand, two hundred eighty-five".