1289280 has 112 divisors (see below), whose sum is σ = 4389120. Its totient is φ = 319488.

The previous prime is 1289273. The next prime is 1289287. The reversal of 1289280 is 829821.

It is an interprime number because it is at equal distance from previous prime (1289273) and next prime (1289287).

It is a Harshad number since it is a multiple of its sum of digits (30).

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 15 ways as a sum of consecutive naturals, for example, 16281 + ... + 16359.

2^1289280 is an apocalyptic number.

1289280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1289280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2194560).

1289280 is an abundant number, since it is smaller than the sum of its proper divisors (3099840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1289280 is a wasteful number, since it uses less digits than its factorization.

1289280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 1289280 is about 1135.4646625941. The cubic root of 1289280 is about 108.8384667904.

The spelling of 1289280 in words is "one million, two hundred eighty-nine thousand, two hundred eighty".