1281000 has 128 divisors (see below), whose sum is σ = 4642560. Its totient is φ = 288000.

The previous prime is 1280989. The next prime is 1281029. The reversal of 1281000 is 1821.

It is a happy number.

It is a super-2 number, since 2×1281000² = 3281922000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 20970 + ... + 21030.

It is an arithmetic number, because the mean of its divisors is an integer number (36270).

2^1281000 is an apocalyptic number.

1281000 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 1281000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2321280).

1281000 is an abundant number, since it is smaller than the sum of its proper divisors (3361560).

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

1281000 is a wasteful number, since it uses less digits than its factorization.

1281000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1281000 is about 1131.8127053537. The cubic root of 1281000 is about 108.6049724872.

Adding to 1281000 its reverse (1821), we get a palindrome (1282821).

It can be divided in two parts, 128 and 1000, that added together give a triangular number (1128 = T₄₇).

The spelling of 1281000 in words is "one million, two hundred eighty-one thousand".