1271289240 has 576 divisors, whose sum is σ = 5136112800. Its totient is φ = 269402112.

The previous prime is 1271289197. The next prime is 1271289247. The reversal of 1271289240 is 429821721.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1271289195 and 1271289204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1271289247) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 43837546 + ... + 43837574.

Almost surely, 2^1271289240 is an apocalyptic number.

1271289240 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 1271289240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2568056400).

1271289240 is an abundant number, since it is smaller than the sum of its proper divisors (3864823560).

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

1271289240 is a wasteful number, since it uses less digits than its factorization.

1271289240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 1271289240 is about 35655.1432475036. The cubic root of 1271289240 is about 1083.2984549455.

The spelling of 1271289240 in words is "one billion, two hundred seventy-one million, two hundred eighty-nine thousand, two hundred forty".