1271840 has 24 divisors (see below), whose sum is σ = 3005100. Its totient is φ = 508672.

The previous prime is 1271839. The next prime is 1271843. The reversal of 1271840 is 481721.

It can be written as a sum of positive squares in 2 ways, for example, as 1263376 + 8464 = 1124^2 + 92^2 .

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1271843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3815 + ... + 4134.

2^1271840 is an apocalyptic number.

1271840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1271840 is an abundant number, since it is smaller than the sum of its proper divisors (1733260).

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

1271840 is an equidigital number, since it uses as much as digits as its factorization.

1271840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7964 (or 7956 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 1271840 is about 1127.7588394688. The cubic root of 1271840 is about 108.3454871308.

The spelling of 1271840 in words is "one million, two hundred seventy-one thousand, eight hundred forty".