1276005640 has 128 divisors (see below), whose sum is σ = 3546466560. Its totient is φ = 402361344.

The previous prime is 1276005623. The next prime is 1276005641. The reversal of 1276005640 is 465006721.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1276005641) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 1444639 + ... + 1445521.

It is an arithmetic number, because the mean of its divisors is an integer number (27706770).

Almost surely, 2^1276005640 is an apocalyptic number.

1276005640 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 1276005640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1773233280).

1276005640 is an abundant number, since it is smaller than the sum of its proper divisors (2270460920).

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

1276005640 is a wasteful number, since it uses less digits than its factorization.

1276005640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1311 (or 1307 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 1276005640 is about 35721.2211437403. The cubic root of 1276005640 is about 1084.6364571644.

The spelling of 1276005640 in words is "one billion, two hundred seventy-six million, five thousand, six hundred forty".