1281271040 has 144 divisors (see below), whose sum is σ = 3629162880. Its totient is φ = 424058880.

The previous prime is 1281271037. The next prime is 1281271049. The reversal of 1281271040 is 401721821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281271049) 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, 257375 + ... + 262305.

It is an arithmetic number, because the mean of its divisors is an integer number (25202520).

Almost surely, 2^1281271040 is an apocalyptic number.

1281271040 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 1281271040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1814581440).

1281271040 is an abundant number, since it is smaller than the sum of its proper divisors (2347891840).

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

1281271040 is an equidigital number, since it uses as much as digits as its factorization.

1281271040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4988 (or 4974 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 26.

The square root of 1281271040 is about 35794.8465564528. The cubic root of 1281271040 is about 1086.1263166383.

Adding to 1281271040 its reverse (401721821), we get a palindrome (1682992861).

The spelling of 1281271040 in words is "one billion, two hundred eighty-one million, two hundred seventy-one thousand, forty".