1281240 has 48 divisors (see below), whose sum is σ = 4165200. Its totient is φ = 341568.

The previous prime is 1281229. The next prime is 1281253. The reversal of 1281240 is 421821.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1420 + ... + 2139.

It is an arithmetic number, because the mean of its divisors is an integer number (86775).

2^1281240 is an apocalyptic number.

1281240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1281240 is an abundant number, since it is smaller than the sum of its proper divisors (2883960).

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

1281240 is a wasteful number, since it uses less digits than its factorization.

1281240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3576 (or 3569 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 1281240 is about 1131.9187249975. The cubic root of 1281240 is about 108.6117545756.

It can be divided in two parts, 1281 and 240, that added together give a square (1521 = 39²).

The spelling of 1281240 in words is "one million, two hundred eighty-one thousand, two hundred forty".