1271440640 has 72 divisors (see below), whose sum is σ = 3051675648. Its totient is φ = 507545600.

The previous prime is 1271440633. The next prime is 1271440669. The reversal of 1271440640 is 460441721.

It is a happy number.

It is a super-2 number, since 2×1271440640² = 3233122602087219200, which contains 22 as substring.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 1104065 + ... + 1105215.

It is an arithmetic number, because the mean of its divisors is an integer number (42384384).

Almost surely, 2^1271440640 is an apocalyptic number.

1271440640 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 1271440640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1525837824).

1271440640 is an abundant number, since it is smaller than the sum of its proper divisors (1780235008).

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

1271440640 is an equidigital number, since it uses as much as digits as its factorization.

1271440640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2035 (or 2021 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 1271440640 is about 35657.2663001526. The cubic root of 1271440640 is about 1083.3414571909.

The spelling of 1271440640 in words is "one billion, two hundred seventy-one million, four hundred forty thousand, six hundred forty".